Access work network from anywhere?

All -

I have a need to access my work network from anywhere, specifically to map a network drive that has a database on it for sharing with my laptop when I'm at home.  The work network has a DSL modem/router and I'm thinking about getting an R7800 to replace the built-in wireless router in the DSL modem.  I'm assuming that I can setup the R7800 with DD-WRT and then put the OpenVPN client on my laptop and then will be able to connect to the work network and access the mapped drive on a desktop.  Will that work?  Do I need to do anything with DDNS?  Or is there a better/easier way to do this?  Thanks for your help and advice.

Mark