thank you very much for your help,
I hoped you to find a solution without awk command (I'm not very used at it)...'cause now I don't know how to handle it
the next step would have been to check only the firt 20char and sum a number in the line...something like this:
AAA 1000
BBB 399
AAA 500
CCC 2000
result:
AAA 1000
AAA 500
tot 1500
BBB 399
tot 399
CCC 2000
tot 2000
thank you again