[phenixbb] command line for reflection file editor

Dear phenix experts, How do I combine Rfree from one dataset with the new dataset under command line? I can do this using reflect file editor GUI easily. But I tried to look up the documentation for phenix.reflection_file_converter and could not find a solution. I am trying to write a script to handle several datasets scaled from HKL2000. I could do this easily in ccp4, but looks like Ctruncate's French&Wilson made the completeness worse than scale.log. Thanks for your help in advance. Best, Zheng