How to cleanup cisco dhcp inserted attributes ?

What would be good way to cleanup attributes that are generated by cisco's dhcp snooping/inserting ? User-Name = "\001\026harjuniitty-ftth-sw1_6" ADSL-Agent-Circuit-Id = "\001\026harjuniitty-ftth-sw1_6" ADSL-Agent-Remote-Id = "\001\024harjuniitty-ftth-sw1" Id like to strip that type 0x01 and length from data so that I would have "harjuniitty-ftth-sw1_6" for user-name. I did'nt see anything obivous in unlang that could do this, and created hack in rlm_preprocess.c As a background, cisco switch snoops dhcp-packet and inserts it's name and port into Option82 of dhcp-packet which is then forwarded to dhcp- relay that first authenticates that request via radius server.