Private Sub UserForm_Initialize()
Dim StrSource As String
StrSource = "[" & ThisWorkbook.Name & "]"
StrSource = StrSource & ThisWorkbook.Worksheets("Sheet1").Name & "!"
StrSource = StrSource & ThisWorkbook.Worksheets("Sheet1").Range("MyList").Address(False, False)
ComboBox1.RowSource = StrSource
End Sub