Help! I need to know about this len

[Kross74]

MC Auto Zoom CPC Phase 2 CCT
80-200mm MACRO 1:4.5 52 8020465

What can you guys tell me about this particular len? Someone is selling it, they don't know anything and I"m just a beginner without a clue when it comes to photography equipment. I have the canon rebel xt. Would this len fit on my camera and is this a good len or not? Also, someone has said that some flim len will fit on digital, depending on the len. Is this correct?

Oh yeah, I actually plan to use the len to take portraits more than anything. I ready have a 50mm that's really good for taking headshots.

Thanks in advance for all your answers!

MC Auto Zoom CPC Phase 2 CCT
80-200mm MACRO 1:4.5 52 8020465