Question : how can i edit this excell ?

Hello i have this CSV file i need to change all numbers that start with 3 to 03 following the number can you edit for me, thanks i tihnk a forumla will do the job.

main.CSV (122 KB) (File Type Details) 

my file

Answer : how can i edit this excell ?

Styleminds, have you tried my code?  Running it once will do exactly what you are asking for. If you want a formula why dont you try something like this =if(strcomp(left(blah, 1),"3"), true: concatenate("0", cell contents