Check character length of each word in a comment

Hi all, i’m an italian newbie on php and wordpress! ??
I’m looking for a script that limit a lenght of a word, because i have a plugin that put in on the homepage the last 5 comments, but if there is a word that has a lot of characters i loose my template structure. Do anyone of you know some that can help me? I have found something with google at this url but i can only image that i have to put in the “function-comment.php” but i don’t know where! ??
i hope in your help!
thank you very much,
p.s.
anyway, the site that i’m building is https://www.akille.net – ENJOY! ??