Thanks Henry.
Though I have replaced my Canon gear with Nikon gear, I retained the mirrorless Canon EOS-M5. Its not a great camera. But its quite good and handy for moving around without being noticed much. I got a EF-M to EF/EF-S mount with this camera that enables use of all canon lenses in this body. You just mount the M42 converter on this mount and you are good to go. With this combination, one can focus to infinity.
I have an M42 to Nikon mount also. But that does not allow infinity focus for M42 lenses. I have ordered a mount with corrective glass from Amazon. Let's see how it works once I get it in hand.
Cheers!