is it possible when a user logs into the board to announce it to irc channel using vB3.5.x_IRC_Post_Announce_v1.3-ShavedApe

yes, you can just add the announce code to the login function.
however, consider that some users can be remembered on computer via cookie, so on this case the user won't have to login into board, and he would still be in your board without it being announced to your irc cahn... :\

lets presume i am blithering idiot and i dont know what i am doing any chance someone could show me how its done lol

the modCP / adminCP has to be logged in everytime, this is the only place I would imagine this would be any use. Unless you want login SPaM.