New Router, 2.4ghz and 5ghz?

So ill try to rephrase. My ADSL modem is a c1000z, single band 2.4ghz. My router is a Linksys WRT320n dual band router.

I would like to know if I can run the modem @2.4ghz AND run the Router @ 5ghz. So end result would be simultaneous 2.4ghz and 5ghz.