Where is the combobox and how did you create it?
If it's on a worksheet and you used the combobox (aka dropdown) from the Forms
toolbar, just rightclick on it and choose Format control.
then click on the control tab and use the Input range box.
If it's on a userform (or from the control toolbox toolbar on a worksheet),
rightclick on it and choose properties.
And change the ListfillRange.
You may have to show that controltoolbox toolbar and go into design mode for the
worksheet version.
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If it's on a worksheet, maybe Data|validation would work for you.
Debra Dalgleish has nice instructions at:
http://www.contextures.com/xlDataVal01.html
And if the list sometimes doesn't extend to all 42 cells, you could revisit
Debra's site:
http://www.contextures.com/xlNames01.html#Dynamic
