ok, what i shoul do is:
read the variable, look for \n cause that will identfy the new line, so once i know how many lines there are on my variable, i should remove every hidden lines, and leave just the last 3. this can be a solution.

the best way could be using an Array but i didn't see anything about it on the manual. so i suppose that i can't store each line on an array ?

any other suggestion ?