How To Add Little Images Within Forums?

[محروم.كوم]

I followed this Thread and it worked great: http://www.vbulletin.com/forum/showthread.php?t=114545

Now what I want to do is when a user clicks to go into a forum and all the threads are there, on the left is the little envelope icons which i want to change to my own style icons.

Anyone has any ideas on how to do this?
What codes to change? __DEFINE_LIKE_SHARE__