Thanks for your reply.
If I tried to resolve my problem making rules. I'll say for the first line I won't process sata until I find another line with the same first word. and If I don't find I won't treat other line because the loop has been finished, you got me ?
my problem is to find for each line a line that has the same first word and I should do this for all lines.
I don't see how to do this in one loop