The Wembley finalists will be decided this year when all four teams play at Macron Stadium, Bolton on Sunday August 5 with both games live on the BBC.
There has been three World Club Challenges held at the venue previously and the same number of Test matches between 1998 and 2007.
Rimmer said: “The Ladbrokes Challenge Cup is one of the most prestigious competitions in sport and the introduction of a semi-finals double header is a fantastic opportunity to showcase two of the biggest games of the year at one event.
“Fans rarely get the chance to watch two games on one day that have so much riding on them.
“We believe this unique event will offer another opportunity for the sport to showcase itself to a wider audience of event goers and casual sports fans.
“By creating the double header we feel we will elevate the games and create a memorable experience for all those involved.”
The first semi-final will kick-off at 12.30pm with the second game starting at 2.45pm.
Phillip Bernie, Head of TV Sport, BBC, said they had been working with the governing body for some time on what will be a “five hour feast of rugby league”.
Leeds Rhinos welcome back Joel Moon, Matt Parcell, Carl Ablett and Anthony Mullally for tomorrow’s Cup quarter-final against Leigh Centurions.
However, they have lost Brett Delaney and Jack Ormondroyd to injuries suffered in Saturday’s defeat in Perpignan.
Castleford Tigers have recalled prop Will Maher from a season-long loan at Halifax ahead of tomorrow’s Super League game at Hull KR.
He could make his first appearance of the season for the club along with Kieran Gill and Tuoyo Egodo while Greg Eden and Joe Wardle return from injury .
After last week’s loss against St Helens, Junior Moors, Greg Minikin and Ben Roberts miss out through injury along with ex-Hull KR prop James Green.
Wigan Warriors prop Ryan Sutton, 22, has agreed a two-year deal with Canberra Raiders starting in 2019.