How do you set two keyboards to act togeather (sharing shift key inputs) for a split keyboard setup.

I use two keyboards to have a split keyboard setup in my

office.  I have a left-handed ‘gaming keyboard’ and a regular compact keyboard. 

The problem is that when I use the shift key on the left keyboard for a key on the right keyboard the system does not recognize the shift key.

The PC has no problem with sharing the key inputs.  Is there a setting to allow the keyboards to

be handled as a unified keyboard?

Thanks!