Export in CSV a string field converted with E+

Dear all,

it is the first time i am facing this problem, but better later than never :-)

Through a formula I am extracting a numeric huge serial number which is stored in a stringvar in this format

everything is ok, the only problem is that when i export the report in csv this number is somehow converted in a numeric so i have 14195E+12.

I tried everything such convert in numeric adding fake ""(space) or use tonumber but nothing.

Could you kindly suggest any idea, please?

Thanks in advance

Best Regards