Best option I can think of is to use an Atlas rail. BT15 or BT17 should work. Remove your sling studs and use those holes to mount the rail. You may need to use machine screws with T-nuts on the back but Atlas also has this hardware.
This leaves you with a picatinny rail on the bottom of your forend. A picatinny bipod mount such as the Larue LT130 can be used to fasten your bipod. The Harris stays on the Larue mount and the mount has a throw lever to quickly remove or attach the bipod/mount combo.
I hope this helps