The Warriors reached their first RaboDirect PRO12 final with a nail-biting win against Munster at Scotstoun a fortnight ago.
Their opponents are reigning champions Leinster - appearing in their fifth straight final - in the Irish side's back yard.
MacArthur has racked up 18 RaboDirect PRO12 appearances this season, in a campaign that has also seen him accumulate four international caps.
His debut - against Samoa in Durban last June - was a special moment for the 27-year-old and he is not expecting Saturday's trip to the RDS to be any different.
"I remember preparing for my international debut and although this weekend will be a totally different scenario the degree of excitement will be the same," he told the Daily Record.
"Everyone in the camp just wants the game to happen as soon as possible now.
"It is going to be a massive climax to a great season and we just can't wait to get out there at the RDS.
"We have won nine matches on the trot to get this far and the aim is simply to keep that momentum going and to stay sharp.
"Most of us have been with the Warriors for a while so we know what each other is feeling and it is about containing that excitement. We need to keep that nervous energy for the right time and get to a peak when it matters."
MacArthur knows the atmosphere in the ground will be enhanced by the occasion - Leinster and Ireland legend Brian O'Driscoll's last match before retirement.
However, he is expecting the travelling Scots to make some noise of their own and spur Gregor Townsend's side onto a maiden RaboDirect PRO12 title.
"I have played there several times and I know the atmosphere will be amazing, particularly with it being O'Driscoll's last match," he added.
"It is going to be so noisy and I'm sure the 3000 Glasgow fans will play their part in that. It is going to be a real battle for 80 minutes - total intensity. But I know we can do it."
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Guinness PRO12
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