Mono source to M/S Signal

How is it possible to make a mono recording, like vocal to a M/S signal.
My goal is to get the Vocal further back in the mix,  without using Delay or Reverb.
As i understand it, with less mid signal and more side signal that would push the vocal back, or
any mono source.

My first thought was to just put a M/S tool on the vocal track, but that did not work, 
as the side signal is not present. 

Then i just wonder, is there a plugin that can make a Mid signal into a M/S signal
so i can tweak the mid's. I am not talking about an stereo enhancer to do this.