Bell will formally be registered on 1 September when the Second Division club's transfer embargo is lifted.
Rangers also have Scott Gallacher, who made his first team debut in a pre-season friendly last week, but McCoist is keen for the 24-year-old to go out on loan.
McCoist said: "We've got two or three goalkeepers who have been put to us but we've nothing new to report on that front so far.
"I must say big Gall has been looking terrific, he really has, but I still think the best thing for him in the long term would be to go out on loan.
"He needs to get playing and get a good few games. He's definitely improving and we can see there's no doubt about that.
"But in an ideal world, if we could get another keeper in that would allow Gall to go out on loan. I think he needs a competitive edge for a season or so."