how to create a shop order for rework on supplier's defect parts but without calculating the material cost

I would like to know, how I can create a new shop order  to rework on defect delivered parts.

but I only need to report the supplier about the time I spent on rework, and not the material cost.

but when I print the NCR, I show the cost like= material cost + extra time cost! whereas I did not have any material costs.

how can I separate the costs in IFS and in the report?

thank you for the help