Constraints as relations between values

Is it possible to set constraints not as numbers, but as, for example, as equality of two angles?

I would like the program to keep to angles equal, without setting their values as equal to some
specific number.

Can it be done without referring to a Z-matrix?

I would suggest a z-matrix, with the angles in question as a common parameter. Otherwise, I don’t think Q-Chem has this built in.