Using separate tickets for two legs on the same train

I have the Sanyo San’in Area regional pass that covers the area between Hiroshima and Osaka. I want to use the pass on its last day of validity to go partway to Tokyo. I plan to go on the Shinkansen from Hiroshima to Shin Osaka using the pass, and then using a pre-purchased ticket from Shin Osaka to Tokyo. I’d like to stay on the same train from Hiroshima all the way to Tokyo. Can this be done? What I want to avoid is having to get off the train in Osaka to insert my ticket in the ticket machine and get back on the train.