When an equation is 'named' they are forced to end with the two character " =". Then XLC knows that it is a named cell and it will enforce automatic subscripting. Automatic subscripting forces all characters after the first character to be subscripted. Automatic subscripting is very important particularly if you remove multiplication signs in equations failure to use automatic subscripting could produce ambiguous equations.
I can see in your case that q" could be useful and I suggest you use the following work-around. Enter 'q"=' into the cell (make sure that it is not 'q" =' i.e. missing the space character). Then the cell will not be automatically subscripted.
I may have laboured the point here - delete the space character before the equals character and it will never again be automatically subscripted.