The 31-year-old former Newcastle United and Chelsea midfielder will attempt to become the first player to score in each of Rangers' first five games of the season.
"It is helping with the confidence at the moment and you feel you can score in every game," Peacock said as QPR approach the game defending a 2-1 lead from the first leg.
But the Welsh club are confident they can spoil Peacock's party and progress into the second round. "We're going down there with the belief that we can win," Cardiff's assistant manager, Billy Ayre, said.
The Luton manager, Lennie Lawrence, will be urging his side to chase an early goal at Bristol Rovers as they seek to repeat their heroics in the same competition last season. The Hatters beat Ipswich, Coventry and Barnsley on their way to the quarter-finals last year but must overturn a 2-0 deficit at the Memorial Ground. "We have got to get the first goal, it's as simple as that," Lawrence said.
The Macclesfield manager, Sammy McIlroy, believes his side can repeat last season's defeat of Stoke in the same competition by winning at the Britannia Stadium. The first leg ended in a 1-1 draw at Moss Rose and McIlroy said: "Hopefully the pressure will be on them with them being the home team. They've got some good players, especially with Peter Thorne and Paul Connor up front."
The Stoke manager, Gary Megson, will blood his new signing, the Norwegian defender Anders Jacobsen.
The Bradford City captain, Stuart McCall, is poised for a dramatic return to first-team football for tonight's match against Arsenal.
McCall has been on the sidelines since the end of June after undergoing Achilles and hernia operations in the space of a week. It led to the 35- year-old midfielder missing the entire pre-season build-up, which included the trip to the Caribbean island of St Kitts.
McCall had originally pencilled himself in to return for the televised home match against Tottenham Hotspur on 12 September, but their manager Paul Jewell may need him at Highbury.
The former Scottish international made a valuable contribution in guiding City to promotion to the top flight for the first time in 77 years last season.
With Neil Redfearn (ankle) and Gareth Whalley (knee) struggling to be fit, Jewell could turn to McCall as the Bantams look to avoid an Arsenal backlash following their 2-1 defeat at home to Manchester United on Sunday.
Jewell, who has striker Lee Mills also trying to shake off a knee injury, confirmed: "Stuart McCall's in the squad. Because we're struggling in the middle of the park, he might be on the bench.
"He's not a bad replacement to bring in - but he's still short of match fitness, although his enthusiasm might just get him through if we need him.
"He trained with us yesterday and he was putting himself about, but that's because he's just so desperately keen to get back in."