[modeller_usage] rigid.txt for PDBs with multiple subunits

Hi,

I'm trying to create a rigid.txt file for an antibody PDB file that contains multiple subunits (ie subunit A, subunit B, subunit C, and subunit D). However, the example in the ncmi_2008_files folder only contains a single subunit. Is there any way one can specify subunit as well as residue number in an rigid.txt file?