I believe you can, but the trick is how to have the computer route the information down the correct connection.
I've seen some people say all you had to do is add a
ROUTE ADD command, but you need to add IP addresses to that. I’m not sure about using this.
I believe you can also do this by using a proxy on your computer and have one browser go through the VPN and have another browser use the proxy and the regular internet connection (or the other way around). The right kind of proxy would allow you to pick the outbound connection to connect to for routing the traffic.
Lastly, and I believe the easiest is you could use a virtual machine. Inside the virtual machine, you can have it connect to the VPN and use that connection. Outside the virtual machine, you can use your regular internet connection. There are some free virtual machine software like VirtualBox.
I don't know of a super easy way. If I were to try this I would use a virtual machines just because I use them all the time and it should be straight forward.
I hope this helps.