Configure OpenVPN on 2.4ghz or 5ghz

Hi, brand new to the forum and networking noob in general. I just purchased an Asus RT-N66U and installed Merlin tonight. I configured OpenVPN successfully, however it affected both the 2.4ghz network and the 5ghz one. I was wondering if there is a way to configure the VPN for only one of them.

I am trying to connect a few devices through the VPN and have remaining devices go through non-VPN and right now whichever wireless network I join, goes through the VPN.

Thanks in advance