Guess the title should of giving it away.
As you didn't mention workbook names I just assumed it was dealing with sheets in the same workbook
Try this in sheet Machine & Customer Details in Front Page.
C10 seems to be a merged cell say I made it B10
Note no error checking. So will fail if purchasing workbook is closed
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address(0, 0) = "B10" Then
If Not IsEmpty(Target) Then
Workbooks("Purchasing Programme test.xls").Sheets("Sheet1").Range("G7").Value = Range("C15").Value
End If
End If
End Sub
VBA Noob
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