[Freesurfer] Problem about the fMRI Analysis of correlation？

Dear Sir, My experiment design is let the two group of subjects watch a movie and calculate the correlation between two condition. Now I get the correlation result from AFNI. I want to calculate the correlation different between the two group by using freesurfer. However the group analysis in freesurfer need the paradigm file to get the constrast file for matlab. But I do not know how can a stimulate as movie can be serve as? I do not know how to write the paradigm at this time. My question is: My stimulate is a 10 minute movie. How can I get the correlation different of two group by using freesurfer? Could you give me some advice?