The Scarlets suffered heartbreak thanks to Tim Stimpson's penalty goal in the final moments of last season's Heineken Cup semi-final against Leicester Tigers.
Should they defeat Perpignan, they will face the winners of the Leinster vs Biarritz quarter-final at a neutral venue in the home country of the victorious team.
But coach Gareth Jenkins is not taking his side's progression for granted.
"We have home advantage in the quarter-final, and we have to make sure we use that advantage.
"Friday nights have really taken off at Stradey Park, we are getting great crowds for Heineken Cup games and the atmosphere definitely helps.
"But you have to respect everyone in this tournament. It's a great tournament that has really taken off," said Jenkins.
Heineken Cup semi-finals.
Toulouse/Northampton v Leicester/Munster
Leinster/Biarritz v Llanelli/Perpignan
Ties to be played on the weekend of April 25-27