So what you're saying is that in a given record you have two fields: part number, part description. You want the combo to display only the part number, but you want the text box to populate with part description. If this is correct:
-Go to the Combo's Properties
-Go to Data-> Row Source
-This will pull up a Query Builder for the Combo Box. Pull in both fields.
-Close the Query Builder. In the Combo's Properties, go to Column Count. Type in '2'.
-Now go to Column Width. Type in 1.5'';0'' or however wide you'd like your visible column; the important thing is to have the column that you want to be invisible to have a Width of 0''.
-You'll now need to alter the VBA code so that the text box populates with the correct field:
Code:
Your_Combo_AfterUpdate()
Me.Your_Textbox=Me.Your_Combo.Column(1)
End Sub
Column Counts always start with a Value of 0, so in my example above, Column(1) would actually be the Second column.
In case you're wondering, yes it's close to XMas and no I don't have a damned thing to do at work.