I am trying to get a listbox to update based on a combobox selection.
Unfortunately my combobox options are W4,W5,W6 etc. which I cannot use
to name ranges in excel. Otherwise I would have used the following
code:

Private Sub ComboBoxgroupW_Change()

UserFormDesign.ListBoxW.RowSource = UserFormDesign.ComboBoxgroupW.Value

End Sub

that way each time the combobox was changed, the list would be updated
with the range that corresponded to the selection. If there is a way
around that, without renaming the combobox choices, that would be
great. here is my second option which is not working at all:

Private Sub ComboBoxgroupW_Change()

I = UserFormDesign.ComboBoxgroupW.Value

Select Case I
Case W4
UserFormDesign.ListBoxW.RowSource = WIDE4
Case W5
UserFormDesign.ListBoxW.RowSource = WIDE5
Case W6
UserFormDesign.ListBoxW.RowSource = WIDE6
Case W8
UserFormDesign.ListBoxW.RowSource = WIDE8
Case W10
UserFormDesign.ListBoxW.RowSource = WIDE10
Case W12
UserFormDesign.ListBoxW.RowSource = WIDE12
Case W14
UserFormDesign.ListBoxW.RowSource = WIDE14
Case W16
UserFormDesign.ListBoxW.RowSource = WIDE16
Case W18
UserFormDesign.ListBoxW.RowSource = WIDE18
Case W21
UserFormDesign.ListBoxW.RowSource = WIDE21
Case W24
UserFormDesign.ListBoxW.RowSource = WIDE24
Case W27
UserFormDesign.ListBoxW.RowSource = WIDE27
Case W30
UserFormDesign.ListBoxW.RowSource = WIDE30
Case W33
UserFormDesign.ListBoxW.RowSource = WIDE33
Case W36
UserFormDesign.ListBoxW.RowSource = WIDE36
Case W40
UserFormDesign.ListBoxW.RowSource = WIDE40
Case W44
UserFormDesign.ListBoxW.RowSource = WIDE44
Case ALL
UserFormDesign.ListBoxW.RowSource = ALLW
End Select
End Sub


WIDE4, WIDE5, WIDE6, etc. are the named ranges that I want to show in
the listbox. Nothing happens when I run this code. what am I doing
wrong?