There is BMC REMEDY ITSM plug-in available for vRO, please refer to the link
have you tried with a 3rd party tool? something that will link the systems since there is no other option? if not, you may check out the marketplaces. my department often has to search for such solutions. at least we see what's on the market. and I dare say there are tons of stuff out there. we've tried six different products, yet just one worked the way we wanted. it's called zigiops.