If you have got CFL's then you can veg your plant and flower! Yes.

You wont get as much as a HPS would get you, but you WILL get bud, as long as you have alot of lights, near it, at the highest wattage you can get.

I am about to do a grow with only CFL's to prove how good it can be if used properly.

Goodluck! Keeep us posted.