Format data on export by Adding characters

hi,

When i export some data for exemple à LOT NUMBER, i want to add a "XX" at the beginning of it when we export the data with an export template

i take from the table OUTPUTM : [OUM]LOT

I'm trying to use =FORMAT$

But i'm stuck on how to express it

For exemple i have the lot number in our database : "00H0450" and i whant to write in output "XX00H0450"

thanks for the tips :-D

jeremy