I have changed my plans on my invoice file and have decided to create a new workbook for each month, name Customer Invoice - July, Customer Invoice - August, etc. Currently I have a macro that takes 4 specific fields of data from each invoice and puts it on the summary page. Now however, I want a complete YTD summary page that will take either all of the invoices from each book or all the data from the summary page of each workbook. Not sure where to start. Thanks for any help.

Currently my macro code is the following:
Sub aaa()

Dim wsSheet As Worksheet, wsSummary As Worksheet
Dim lRow As Long

Set wsSummary = Workbooks("Customer Invoice - July.xls").Sheets("Combined")
lRow = 2

For Each wsSheet In ThisWorkbook.Worksheets
    If wsSheet.Name <> "Combined" Then
        wsSummary.Cells(lRow, 3).Value = wsSheet.Range("E2").Value
        wsSummary.Cells(lRow, 2).Value = wsSheet.Range("E3").Value
        wsSummary.Cells(lRow, 1).Value = wsSheet.Range("E7").Value
        wsSummary.Cells(lRow, 4).Value = wsSheet.Range("E32").Value
        lRow = lRow + 1
    End If
Next wsSheet

End Sub