BASIC is an interpretive language. Someone would have to port over an interpreter first.
I think there may be some utilities to convert BASIC programs into executable code, but I don't think they would be compatible with GP32 development.
And if you don't like C, you could always try C++. The main reason they teach C first in classes is because C is purely fuctional, while C++ has some object-oriented structure (hence the ++, mostly). I suppose they'd rather you learn the fudementals first, before you have a chance to goof-up OOP.