Nero Wave editor: Increasing volume in one channel

I just started using Nero Wave Editor. I have a .wav file (song) in which the volume for the left channel (speaker), is much lower than the volumne for the right channel (speaker). It seems like the song was originally recorded that way. I would like to save the file, after increasing the volume in just the left channel a bit more. How do I do that with the Nero Wave editor or perhaps some other Nero Application?
Thanks.
Richard