Bass emulation ..??

If your going for a true bass guitar sound, the guitar will never cut it with effects that lower it octive or pitch. If you going for a guita sound, thats seems like a bass, just try what i said above
Cj

As Cj said, you'll probably have difficulty making your guitar sound like a realistic bass. But check out the bass guitar patches in the bundled soft synths. My favourite ones are in either Dropzone or Dimension LE. I don't remember which one. They sound really good (to me), but it's a lot of work programming, since you'll be utilizing midi in this case.