A new question for the experts having problems finding the correct way to use a value list with text and number to then show only a fixed number in the fiels

Hi All

I need to create various value lists with a text and number description(all are unique), I then need when a user selects a description it will only display the number (not the text) in the same or a different field.

example "03  bla bla bla" , would only display 03 after selecting in the value list.

I have used replace text and substitute text but I'm not sure if that's the correct method , also I cant get either to work on more than 1 value at a time  in the calculation.