EPC from RSPAN?

I'm curious to know if the following is possible and if someone has experience setting it up.

I have a pair of remote Cat 4500s. One, in the mdf, has ip base. The other, in an idf, has lan base.

I need to do a Embedded packet capture from a device connected to the IDF switch. However, since it has lan base it doesn't appear to support EPC. So I was going to setup an RSPAN from the IDF switch to the MDF switch. Then setup the EPC on the MDF switch and save it locally then grab the file.

Can this actually work? I'm having difficulty figuring out the syntax on the EPC to get the traffic from the RSPAN vlan.

Thoughts or suggestions?

Thanks for your time