Michael,
Thanks for the suggestion. I'm running into problems creating my drop down objects, however.
I've created a drop down which I've stuck in the cell above my grid. Here's what I did in each step of the editing of that drop down:
Step 1: I named the caption of this dropdown "Sales Rep", and changed it to be read only.
Step 2: I didn't add any actions
Step 3: I didn't create any validation rules (these are read only drop downs)
Step 4: Selected table "SalesOrder", and field "SalesRep". In the box where I can select a value as default, there's a long list with many repetitions of the various Sales Rep names, as well as blank lines. I want the default to be blank (as in don't filter until a name is selected).
Step 5: I didn't choose any filters, I want every Sales Rep that ever was put on a Sales Order to show up on that drop down.
Step 6: No changes here, every role has permission.
After I apply those changes and publish my screen, though, the drop box is nowhere to be found! You can see the caption text, and empty space next to it where the drop box is supposed to show up, but the actual box with the down arrow and whatnot is missing.