Separating voice from backing music

[Mim]

I don't know if this is even possible with WavePad, or which software may be able to do it (Mixpad?) but I know somehow it can be done as I have seen it on many Youtube music videos. What I need to know is how to separate the voice from the instrumental backing on a track but keeping both without deleting one or the other.

The reason I wish to do this, is so that I can create a duet between two artists while removing the instrumental portion of one audio retaining only the voice to be mixed with the other.