IF Exists or on Error Then - Skip Code- How to write code?

The Workbooks.open filename seen below prompts an error because it does not exist. I want a way to either check if the workbook exists and if it does then continue code and if it doesn't then skip part of the code and resume. Or I want a way to on error of trying to open workbook skip this part of code and resume at this place. I believe either one will work but i am not fimilar with the If and objects enought to know how to write it as i am self taught. If you reply with an answer and put it into the code please also list the answer outside of the code as well please in a seperate code window. Thanks.

Workbooks.Open Filename:= _
"I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed\DATE6_GA_LocationSummaryReport.xls"
Columns("A:A").Select

Sub WeeklyIntegrationSetup()
'
' WeeklyIntegrationSetup Macro
'
'===================================================================================================
'CTRL-F REPLACE "DATE1" W/1ST DATE OF WEEK, FORMAT AABBCC
'CTRL-F REPLACE "DATE11" W/1ST DATE OF WEE, FORMAT AA/BB/CC
'ETC...........................................................
'CTRL-F REPLACE "DATE6" W/1ST DATE OF WEEK, FORMAT AABBCC
'CTRL-F REPLACE "DATE66" W/1ST DATE OF WEE, FORMAT AA/BB/CC
'===================================================================================================

'
    Application.DisplayAlerts = False
    Workbooks.Open Filename:= _
        "I:\ACCOUNTING\Clear Payments\Current Month\zIntegration template BLANK.xls"
    ChDir "I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed"
    Workbooks.Open Filename:= _
        "I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed\DATE1-DATE6_CIC_DailyFile.xls"
    Range("B7:W7").Select
    Range(Selection, Selection.End(xlDown)).Select
    Selection.SpecialCells(xlCellTypeVisible).Select
    Selection.Copy
    Windows("zIntegration template BLANK.xls").Activate
    Sheets("FeeSetup").Select
    Range("B7").Select
    ActiveSheet.Paste
    Selection.End(xlDown).Select
    ActiveCell.Offset(1, 0).Select
    
    Workbooks.Open Filename:= _
        "I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed\DATE1-DATE6_GA_DailyFile.xls"
    Range("B7:W7").Select
    Range(Selection, Selection.End(xlDown)).Select
    Selection.SpecialCells(xlCellTypeVisible).Select
    Application.CutCopyMode = False
    Selection.Copy
    Windows("zIntegration template BLANK.xls").Activate
    ActiveSheet.Paste
    Windows("DATE1-DATE6_CIC_DailyFile.xls").Activate
    ActiveWindow.Close
    Windows("DATE1-DATE6_GA_DailyFile.xls").Activate
    ActiveWindow.Close
    Sheets("CkbkSetup-single dist_site").Select
    '===================================================================================================
    '====================================================================================================
    
    Workbooks.Open Filename:= _
        "I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed\DATE6_CIC_LocationSummaryReport.xls"
    Columns("A:A").Select
    Selection.NumberFormat = "mm/dd/yy;@"
    Selection.ColumnWidth = 10
    Range("A6").Select
    ActiveCell.FormulaR1C1 = "date"
    Range("A7").Select
    ActiveCell.FormulaR1C1 = "DATE66"
    Range("A7").Select
    Selection.Copy
    ActiveCell.Offset(0, 4).Select
    Selection.End(xlDown).Select
    ActiveCell.Offset(0, -3).Select
    ActiveSheet.Paste
    Application.CutCopyMode = False
    Selection.Copy
    Range(Selection, Selection.End(xlUp)).Select
    ActiveSheet.Paste
    Application.CutCopyMode = False
    Range("A7:N7").Select
    Range(Selection, Selection.End(xlDown)).Select
    Selection.Copy
    Windows("zIntegration template BLANK.xls").Activate
    ActiveSheet.Paste
    Selection.End(xlDown).Select
    ActiveCell.Offset(1, 0).Select

    Workbooks.Open Filename:= _
        "I:\ACCOUNTING\Clear Payments\2013\2013-01\Completed\DATE6_GA_LocationSummaryReport.xls"
        Columns("A:A").Select
    Selection.NumberFormat = "mm/dd/yy;@"
    Selection.ColumnWidth = 10
    Range("A6").Select
    ActiveCell.FormulaR1C1 = "date"
    Range("A7").Select
    ActiveCell.FormulaR1C1 = "DATE66"
    Range("A7").Select
    Selection.Copy
    ActiveCell.Offset(0, 4).Select
    Selection.End(xlDown).Select
    ActiveCell.Offset(0, -3).Select
    ActiveSheet.Paste
    Application.CutCopyMode = False
    Selection.Copy
    Range(Selection, Selection.End(xlUp)).Select
    ActiveSheet.Paste
    Application.CutCopyMode = False
    Range("A7:N7").Select
    Range(Selection, Selection.End(xlDown)).Select
    Selection.Copy
    Windows("zIntegration template BLANK.xls").Activate
    ActiveSheet.Paste
    Selection.End(xlDown).Select
    ActiveCell.Offset(1, 0).Select
    Windows("DATE6_CIC_LocationSummaryReport.xls").Activate
    ActiveWindow.Close
    Windows("DATE6_GA_LocationSummaryReport.xls").Activate
    ActiveWindow.Close
    '====================================================================================================

    Application.DisplayAlerts = True
End Sub