Karaoke Forums

Hi all.
Like most, there are some songs I like and some others that I don't like at all.
Then there's another category of (Karaoke) songs that I never tire of listening and singing to.
Lately it crossed my mind that it would be a great idea (at least for me, ) if I could be able to "cut and paste" parts from different song and build a few medlies to my liking.
The problem is I just don't know how to do it or if it could be done at all. I know I could "join" the music part, do the same with the lyrics and the author the whole thing a-new. But that is time consuming and the end result is somewhat not guaranteed to be perfect.
Any suggestions and/or recomendations will be greatly appreciated.
Thanks in advance.

PS. I have both Power Karaoke and Karaoke Builder software, and Adobe Audition.