If you are interested in the ULTIMATE VBA reference for Excel, go for a John Walkenbach Book. Most of the VBA techniques I know comes from there. The man knows the application inside out and he has a captivating style of writing. In his book you'll find things the Redmond chaps didn't have the vaguest idea about until John said so.
By virtue of the fact that each of the applications using VBA as their programming language has its own unique set of objects/properties/methods apart from some which are common across applications, it is unlikely you'll find a useful general VBA referance book - and all application-specific books give you a comprehensive treatment of the general VBA language philosophy.
Good luck
mala
mala_rs_singh@rediffmail.com