Customizing the edit template

Hi-

New to EasyBlog. But, not to Joomla. I integrating this to a website on 3.x What I need is a good microblogging system. EasyBlog was hands down the best blogging system I have found. The only issue is I need to limit the characters allowd in a blog submission or edit to how many someone may post. In otherwords, the reverse to the "minimum character" to post.

I was looking at using this javascript:
http://www.mediacollege.com/internet/javascript/form/limit-characters.html

To not only limit how many characters can be used, but also show how many characters are left.
My question is, which file do I need to edit? And if possible the best point to insert the edit.

I wouldn't be against using the HTML edit version:
http://www.w3schools.com/tags/att_input_maxlength.asp

My thought was to make a duplicate of the edited page and place it in my html folder of the template being used. so when upgrades are given I won't lose that edit.

Any thoughts, advice or help with this would be most appreciated!

Best regards,
-Justin