Set Allow Edits to Yes and set the Locked property of your fields (excluding the Combo Box) to Yes.
This will have the same effect but you will be able to choose an item in your Combo Box.

Thanks Kevin, locking all field properties for viewing and unlocking for editing is an approach I was trying to avoid only because with the main form and all sub forms there are a lot of fields. I was hoping there was some method similar to the navigation buttons. However, thinking about it I could set up a subroutine and pass the form/subform name to that routine to lock/unlock field properties. Thanks for the suggestion. I think that will work.