What is your target processor?
I sometimes use MATLAB to help design my DSP algorithms. Then I write a C program (if targeting a PC), or I write HDL (if targeting an FPGA). I don't use any conversion software.
When writing C for a PC (Intel or AMD CPU), I usually don't bother with fixed point, because floating point runs about as fast, and it's a lot more convenient.
When writing HDL for an FPGA, I simply use integer arithmetic, and keep track of the required scaling factors and shifts along the way.