Each instrument track has its own form of notation. If you want to change the number of strings on a guitar score/tab, for example from a 6 string guitar to a 7 string guitar, you have to create a new track and transcribe you track using copy/paste.
You can also combine two tracks (guitar and bass) and copy/paste them into a piano track to play your composition on another instrument. If you are not comfortable composing a piano track with standard notation, edit your track on the guitar then change the soundbank to reproduce the sound of a keyboard.