Just for a better understanding, are you wanting the number translated in to text through some code OR are you wanting to enter a number and recieve back txt assigned to that number.
If you are looking for the latter, I would recommend useing a combo box that would fill in another filed based on the selection made. Say you have a tbl with only 2 fields, Num and TXT. For every Num you have assigned TXT. Create a form and set the datasource to the table. Now place the TXT filed on the form as a textbox. Use the wizard to place a combo box on the form and use the third option the lets the selection in the cobo box fill out the form.
Take a look at the example.