Hello John,
This tests to see if the file is open, and if not, it opens the file:
Dim SourceWorkbook As Workbook
Dim Area As Range
Dim SourceWbPath As String
Dim SourceWbName As String
SourceWbPath = ThisWorkbook.Worksheets("some sheet").[ab1]
SourceWbName = Mid(SourceWbPath, InStrRev(SourceWbPath, "\") + 1)
On Error Resume Next
Set SourceWorkbook = Workbooks(SourceWbName)
If Err <> 0 Then
Err.Clear
Set SourceWorkbook = Workbooks.Open(SourceWbPath)
End If
On Error GoTo 0
Regards,
Patrick