i just found a free C compiler and programming in C is not too bad compared to Python (i like functional programming). right now i use python as a bridge between Panda and a DLL made by myself - the DLL does most calculation and python just reads data from DLL then call Panda APIs such as setPos, setHpr… if Panda APIs could be called from DLL, then the program would be more simple, and fast 
You can use interrogate to generate C bindings for Panda. This is how we originally interfaced to scripting languages. However, it would be easier to call Panda from C++ code, and called those C++ functions from your C code.