McCoist was furious when Mohsni was red carded in the SPFL League One showdown with Brechin City at Ibrox on Saturday.
The 26-year-old will miss the league games with Ayr United at Somerset Park on February 15 and Stenhousemuir at Ibrox on February 22.
He has now been booked five times in the 2013/14 campaign - and will be banned for another game if he is yellow carded again.
McCoist held talks with the French- Tunisian centre-half before training at Murray Park and urged him to control his temper.
Speaking to the official Rangers website, McCoist said: "I was very angry and disappointed on Saturday. Bilel knew that the sending off was silly and needless. It put us under a little bit of pressure.
"We had a good chat about it and he's in total agreement with the sending off, as you would expect.
"It was a silly thing to do but now we move on.
"We don't want it to happen again obviously and hopefully we can learn lessons from that particular incident."
He added: "There was no injustice in the sending off.
"We just have to direct Bilel's passion and his natural aggression and sometimes he needs to take a step back.
"If that means counting to 10, he needs to count to 10.
"He's no use to us if he's suspended. He's not any use to the team sitting in the stand."
"He's of use to us on the park winning games. I thought he played well in the first half. We need to see more of that."