Forumlar / Cotonti / Support / mod_rewrite HELP needed

It isn't a problem of plugin or custom function (I've already created system/functions.custom.php, addressed by datas/ultrans.dat, that translate Cotonti urls for my needs).
The problem is only in RewriteCond & RewriteRule syntax.
I'm trying to understand how to tell Apache mod_rewrite module to read the value of last string passed by backreference among the two last dashes, like Trustmaster exaple does (unfortunately, only for the second part of url, after the domain part, 'cause that example uses only RewriteRule and not RewriteCond).

Indeed, I don't want to pass more values to list.php, but to read the right part of rewritten url and then pass it to list.php as c=structure-code value, got it?

My goal is to tell the Server:

Read this string (the one in red):
http://cat.sangelo.net/blablabla/subcat/) (I don't mind what is passed by the other blablabla variables, 'cause I'll write them right with a custom function) and pass it to list.php as c=structure-code

In other words:
Read this url: http://sport.sangelo.net/blablabla/basket/ and give me http://www.sangelo.net/list.php?c=basket

Got it?

I'm sure this is possible, only finding the right RewriteCond/RewriteRule syntax.