I got decent PR on my youtube vids... does this help?

Hi everyone, I have a question, I understand one factor for getting page rank to my domain is having a Link, to my page, from other websites which have PR correct?

on my youtube profile i have a page rank of 4/10 according to google toolbar on firefox

i have a total of 3 videos, on their individual page each = 3/10 on firefox google toolbar....

this is probably a stupid question but if i put a link to my domain on all of these pages, this should get my domain PR ?
this is a stupid question even to me, but i just need to make sure..

i wonder because i know people spam youtube comments all the time, so i thought maybe PR on youtube vids might not give my domain PR or something, cause its easy to spam youtube pages so... i dunno