Bonnie,
You are using teh grid ok when using related fields. You can set the column to Boudn .F. and use the controlsource for the textbox and combo separately. You will need to make the column sparse .f. to see the textbox though and you will need to change the CurrentControl to switch between the combo and the textbox. You can try the DynamicCurrentControl property if you can define a condition for each control.
Grid more complex than browse, well with flexibility comes complexity.