no b/c cfl bulbs do not put off heat light incandescents... you have to acheive a basking temp of b/w 100-110 F for dragons... I would say that you need at least a 60 watt bulb to get those temps, dont think a 40 watt will do it unless its really close to the dragon.
A CFL would be fine to use for supplemental light...in fact I've recommended them numerous times for just that. If possible, use one marketed as "daylight" in color; these typically range from 5000 kelvin to 6500 kelvin. The package will be marked with all this info.
I know you have your basis covered, but for the sake of clarity...you'll still need a heat source and a UVB source.