The County ended day two at Cheltenham College on 353 for seven in their first innings, a lead of 36 over the home side at the halfway stage of the four-day clash.Rickelton top-scored for Northants, passing 50 for the fifth time in his four games for the club as he made 95, while support came from Luke Procter (78) and skipper Will Young (61).
James Sales will resume his innings on Wednesday, unbeaten on 21.
South African Rickelton was frustrated that he failed to go on and scored a third century in four matches for the County, and admitted he and his team-mates should already be in a more dominant position.
"I was disappointed to miss out on a hundred, but that happens in cricket sometimes," said the 26-year-old.
"We are disappointed as a team to be only around 40 ahead when it could have been nearer three figures had one or two of us gone on to big scores.
"That is something we need to work on with our remaining wickets because it is going to be tough batting last on a pitch, which already has a fair bit of rough and is turning."
Left-arm spinner Zafar Gohar was the pick of the attack for the home side, claiming four for 93 from 31 overs, and Rickelton is expecting the Pakistan international to be a danger in the second innings as well.
"Zafar Gohar presented a tough challenge," admitted Rickelton.
"It was frustrating that he had me caught behind down the leg side, but I will be back to do battle with him in the second innings."
This match is Rickelton's last one for the County before he joins up with the South Africa squad for their Test series with England.
He has relished being part of the 150th Cheltenham Cricket Festival, but is expecting things to be a little bit tougher against Ben Stokes's men.
"I have never played on a ground as beautiful as this back home," admitted Rickelton.
"The whole county cricket experience has been great for me, although I expect the pitches and the balls to be a bit different when the Test Series begins!"
Play on day three at Cheltenham starts at 11am on Wednesday.