Ulster travel to Cape Town today for the clash at the DHL Stadium after putting Munster to the sword last Friday.
Edinburgh gifted the Stormers two of their three tries from bad defensive mistakes and also caused the South Africans trouble in attack.
“There were parts and aspects of that game that we will take encouragement from,” said Soper. “And we have a game that we can go and really challenge them.
“But there were a few warning shots fired by the Stormers as well.
“They are a pretty dangerous team and you have to stay on it for 80 minutes.
“It was no surprise that Edinburgh fired a few shots out there because they are a really good team but we have certainly taking some learnings out of it.
“We have to draw on the experience of going there (in March), what did we learn and that will help us in our preparation.
“The last time we were there it was the first time for almost everyone, being in that stadium...for some of the guys it was their first time touring in South Africa.”
Soper is confident that Ulster’s young guns won’t suffer stage fright in the semi-final.
“We have got some young guys but a lot of those young guys have actually played a lot of the rugby this year, so they are gaining experience every time we get out there,” he said. “They have got a lot of confidence and I think everyone feeds off that as well.
“We are certainly not going to go to the Stormers and be loose and try to play a game of basketball.
“But we also just want to go and play our game and some of the strengths of those young guys would be to let them play and give them opportunities with the ball in their hand.
“So that will be part of the plan.”
Soper confirmed that full back Michael Lowry will miss the rest of Ulster’s season after undergoing surgery for the facial injury he picked up against the Sharks.
Stewart Moore deputised for Lowry in the No15 shirt against Munster and seized the opportunity with aplomb, scoring two of his side’s five tries.
“Stewart is such a talented footballer,” said Soper. “As a centre it is pretty tough when you have Stu (McCloskey) and James (Hume) in front of him to force your way into the team the way those two guys have played this year.
“Stew has been patient, but he is such a good footballer he has been able to show us things in training that we know and have the confidence that he is able to go and play at full back.
“He has had a few opportunities and he is doing really well and is continuing to learn.
“I was really pleased for him that he has taken this opportunity, it is desperately unfortunate for Mike that we get to this time of the year where he has contributed so much to our success and he doesn’t get a part to play in knockout footie...but that is the nature of the job.”
q Danny Wilson has been sacked as Glasgow’s head coach in the wake of Saturday’s humiliating defeat by Leinster.
The Welshman replaced Dave Rennie in the summer of 2020 but has now paid the price for the abject 76-14 loss in the United Rugby Championship
The decision was taken by the club and Scottish Rugby following a meeting with Wilson yesterday.
Warriors managing director Al Kellock said the club “needed to act”.
“The recent run of results has not been acceptable and has had a significant impact on everyone connected to the club,” he told Glasgow’s website. “We are a proud organisation and want to be competitive week in, week out and we felt therefore a change of head coach was the right step to take.
“It is never pleasant to have to make changes to our team, but we needed to act. I’ve enjoyed working closely with Danny and know he has given a huge amount to Glasgow over the past two seasons and for that I’d like to thank him and wish him well.”