Hi Dale, Kim
It's unlikely that would be a picklist object if it's not already a picklist. However, the resolution is fairly simple:
1) make a note of what the field is already data bound to (check the text property) - it will link to the data item
2) From the Architect palette (F12) - drop a new picklist object onto the form
3) From the new object's PicklistName - select your new picklist created earlier
4) Select the Text property - hit the ellipse - select the data item remembered from step 1
Save | Release (F10)
Whisk, stir, bake on gas mark 5 and leave to set for 20 mins mmmm :-)
Regards
Mike