How to keep leading zeros in data export and when combining fields

Hi everyone!

Using custom validation (matches regex ^[0-9]{2}$ ) I make sure that my participants always enter two digits in response to a question, i.e. "08" must be entered instead of "8".
However, in data export and when concatenating variables, “8” still shows up as “8” even though “08” was entered.
 
However, I would also like to export (e.g. to csv or excel) this result as "08" not as "8".
Moreover, I would like to concatenate combined variables in the data section and here "08" should be also used instead of "8".
 
Is this possible?
 
Thanks.
 
Best