Thank you for all the suggestions. I initially used the technique suggested by Axel, but didn't want to have to keep remembering the scaling factors. I indend to use the Trace command, which would require post multiplication and I have quite a few matrices, so keeping track of factors isn't practical. If I do what Marvin suggests, (which is how I desired to solve the problem) it means that the Trace command will not work.
The factrix command is ideal, so I use this. Thank you very much for all your help and suggestions; very much appreciated.
I am generating representation matrices for Tetrahedral and Octahedral Double Groups, so I need the character (trace).