I have mistakenly put screw back into wrong entrance on mac...can technicians remove it . tried glue .no luck?

Glue? What did you use glue FOR? I take it you put the screw into the wrong hole and screwed it in, right? And now, you can't get it back out again? What you need in the mechanics trade, is called an "easy-out". This is similar to a tapered drill with left hand threads, so as you attempt to unscrew (loosen) the screw, the spiral on the easy-out digs into the top of the screw to grip the screw and force it to loosen. You can get these at any store which sells decent hand tools. Sears, for example. They are not cheap. A set of 3 at Sears (each is double ended, for 6 different sizes) runs about $20. If you have a toolbox and deal with bolts or screws, you should have a set of these.