InfoPath Dev

Hello, Im looking to update a field, inputted by a user, that would re-format the field after input. Example: User inputs 1234 Output: A1234C01 As you can see, i want to use the input to produce the Output. The Output would always have the same format as example "A C01" Is this possible?

There might be several ways to do that.... see attached sample form.

Solution 1:  if you can have output in different field, this is most common style -- Create another field, say 'reformatted', and set its default value as  concat("A", UserInput, "C01")

Solution 2: if it is essential to use the same field and overwrite it, I'd set a rule at the timing of Submit. also added a status field, so that updated fields will not be applied the concatenation again..