Macro code for moving between files

I am trying to run a macro that will open a file from a folder and manipulate the file in various ways. Once complete it will do the same with the next file in the folder, etc. The manipulation includes copying from a source workbook that is already open (Dept macro 2014 Testing.xlsm in my example). The macro should copy data as well as an entire sheet from the source workbook.

I am challenged with the code to use for the workbook(s) opened when moving from window to window (source workbook to workbook opened from list). I am ok with the source workbook as I just use that workbooks name. I can't figure out out to reference the opened workbook(s).

Do While FileName <> ""
  Set CurrentWB = Workbooks.Open(PathName & FileName)
  With ActiveSheet
    Rows("1:5").Select
    Selection.Insert Shift:=xlDown
    Windows("Dept macro 2014 Testing.xlsm").Activate
    Sheets("DBC").Select
    Selection.Copy
    Windows("CurrentWB").Activate
    Range("O3").Select
    ActiveSheet.Paste
    Windows("Dept macro 2014 Testing.xlsm").Activate
    Sheets("Category Summary").Select
    Application.CutCopyMode = False
    Sheets("Category Summary").Copy After:=WorkbooksFileName.Sheets _
        (1)
    Sheets("Sheet1").Select
    Range("E7").Select
    ActiveCell.FormulaR1C1 = "2710"
    Sheets("Sheet1").Select
    Sheets("Sheet1").Name = "2710"
    Range("A26").Select
End With
  CurrentWB.Close True
  FileName = Dir()

I have made the line of the code where I need help with blue.


Thanks