Concrete example: Suppose I have two (2 x 2) matrices that have entries as operators or other non-commutative object.

In the following example Maple treats the entries like numbers:

with(linalg);

R:=matrix(2,2,[R11,R12,R21,R22]);

X:=matrix(2,2,[A,B,C,D]);

Res:=multiply(R,X);

How can I ensure that these are not commuted like ordinary numbers?

The second part of the question, is how I can also prevent arbitrary application of associativity if I so choose.