Sorry, I forgot to come back to this.
You should be able to pass these exactly as is currently done with the RetroTS.py output. So make a text file of regressors, one per column, where for each slice there are all the regressors you want. For example, if you create 10 regressors per slice and there are 30 slices, then the file should have 300 columns where column 0-9 is for slice 0, 10-19 is for slice 1, etc.
It is also passed as one file per run (since regressors are created per run), using the same sort of format:
-ricor_regs sb23/RICOR/ricor_regs_run1.1D \
sb23/RICOR/ricor_regs_run2.1D \
sb23/RICOR/ricor_regs_run3.1D \
Does that seem reasonable?
- rick