GLM with multiple regressors in first level analysis using FSL

Hi everybody,
I have a question that I would really appreciate it if you could reply and help me with it. I am trying to create a GLM with more than 100 regressors using FSL for my research (first level analysis in FSL), but I am not sure how to exactly do that, I can create my GLM using MATLAB but I do not to how to use it through FSL. I even made design .mat and design .con files for GLM and I cannot find a way to insert it in FSL .
Best,