We analyze PCBs on a dual column with two uECD detectors. We are required to check the RPD between the two signals and I would like to add this into the sample report. I am currently using a report that has a table with the compounds grouped by signal and the amounts summed. I'd like to get the RPD of those two summed amounts but I can't figure out how to make this happen. We are using Openlab CDS Chemstation Edition, Ver C.1.05 
I could also separate the tables by signal and have two tables per sample where the the entire row for the compound amount is summed, but I am not sure how to get the RPDs for those values either. I have attached the report I am currently working on.
Any help is appreciated! Thank you.