How can you setup a combobox so that the control source is not what is displayed in the control, only written to the table?

For example,
Combobox.controlsource = master.textid.
Combobox.rowsource = table1.description, textid.
When the combobox runs you should only see the values from table1.description and when selecting one of these descriptions the value of table1.textid should replace master.textid.