Someone knows how I have to do in order to change a "text field" text if a Combo Choice have an exact text, using trigger?

Someone knows how I have to do in order to change a "text field" text if a Combo Choice have an exact text, using trigger?

In the "after update" trigger of the"Combo Choice" .. do something like
if text('Combo Choice') = "Exact Text" then
'Text Field' := text('Combo Choice');
end;
**disclaimer.. code not tested.. your mileage may vary. :)