Appearing in his first game since early November, Doherty replaced Dave Winfield midway through the second half and headed home Sam Wood's in-swinging corner in the 81st minute.
Joel Grant had given Wycombe the lead in the seventh minute when, after Dean Morgan squared a low cross into his path, the winger outpaced Dale Tonge to slot home.
The Millers barely threatened in the first half with only David Noble's tame strike to show for their efforts but led thanks to a double from top scorer Daniel Nardiello after the break.
Nardiello out-jumped Wood to meet Liam Ridehalgh's pin-point cross in the 51st minute and grabbed his second just after the hour, this time volleying home Ben Pringle's low cross.
And after Doherty had levelled things up, Wycombe had Jordan Archer to thank for the point after he saved a stoppage-time Claude Davis header.