Instuctions on how to assign a form query to a field:

1.      Open a form.

2.      Click on the field.

3.      Select for the drop down menus at the top of the screen:
Tools->Search Function->Define 

4.      A window will appear. Click on Search by Saved Query. Double Click on the long gray box below that option. The Query Manager will open. Select the query you wish to run on the field you selected.

If you would like to have the value automatically populate when something else happens on the form, check the Auto Refresh When Field Changes box. From the drop down box below that option, select the field that will "trigger" the query to run on the field you selected.

5.      To run the query on demand on the form, press Alt+F2. To change the field’s query assignment later you can press Alt+Shift+F2 and the window above will be displayed. You can also follow the original drop down menu path listed above to perform the same action.