That game was played out in front of a record home crowd at Murrayfield but at the Aviva Stadium on Saturday Edinburgh fans are likely to be outnumbered by their Ulster counterparts.
However Laidlaw is confident that the extra Irish supporters will not affect Edinburgh as they seek a first-ever Heineken Cup final appearance.
He said: "It will be comparatively easy for the Ulster people to get to Dublin - they can just jump on a bus or a train - but as long as they are not on the pitch, they won't bother us.
"The noise our fans made was incredible at Murrayfield when we beat Toulouse in the last round - they played a huge part in the success.
"Dublin is a neutral venue but we know the Ulster contingent will be there in force. So we need Edinburgh supporters to take up the challenge off the park while we do the same on it.
"We will be the underdogs and the Ulster fans will expect their team to win.
"I am quite happy for us to be the underdogs - just look at what has happened in the tournament so far.
"The opposition have been favourites in every tie and now we are in the semi-finals. The tag will certainly not affect us this weekend."