Millen, who was asked to be in charge of the game at Loftus Road little over 24 hours before kick-off, would have been pleased with his side's endeavour but a lack of quality at both ends meant neither team were able to carve out a decisive chance.
Jason Puncheon went closest when his curling shot hit the post in the first half and Rangers also had opportunities in the second period but a lack of quality finishing meant Harry Redknapp's men failed to secure a fourth consecutive home victory.
Rangers may have felt Palace would be there for the taking after Warnock was relieved of his duties following just one win in 12 matches, but there were no signs of despondency from the Eagles, who seemed eager to impress their new boss from the outset.
Both teams contributed to a lively start but it took quarter of an hour for either keeper to be tested as Charlie Austin fired an ambitious volley from outside the box straight into the hands of Julian Speroni.
Yannick Bolasie returned the favour three minutes later with a curling long-range strike at the other end but Rob Green was equal to the shot.
Clear-cut chances continued to elude both sides but Puncheon almost opened the scoring against his former club when his curling left-footed shot beat Green but came back off the post.
Palace enjoyed the majority of possession before half-time and Millen would have been pleased with his players' energy and tempo, but the Eagles' creative outlets - Bolasie, Zaha and Puncheon - were all too wasteful in the final third.
Zaha escaped the attention of Steven Caulker shortly before the break but his scuffed shot from an acute angle rolled harmlessly wide of the far post.
Leroy Fer was unlucky to see his volley from the edge of the area dip narrowly wide after the restart but QPR began the second period as sloppily as they ended the first, misplacing a series of simple passes in midfield.
Fer eased the home fans' growing frustrations with a superb 30-yard half-volley on the hour and from the resulting corner Austin went close but his header was deflected over the bar.
Palace were increasingly reliant on the counter-attack and Bolasie and Puncheon could have made it pay, the former taking too long to get his shot off after wriggling free of Mauricio Isla, before the latter saw his stinging shot denied by Rob Green.
It was Rangers though who looked the more likely to snatch all three points and the hosts nearly did so in the 74th minute when Caulker's header was cleared off the line by James McArthur.
Both teams pushed forward in the game's latter stages as the contest opened up and Palace almost nicked it at the death when Puncheon's shot was palmed out by Green, but Barton just managed to scramble the ball away from the incoming Fraizer Campbell to ensure the spoils were shared.
Source : PA
Source: PA