%                Expression Operator                            MASM Operator

  %text

    Causes the assembler to treat text as an expression. MASM will compute
    the expression's value using the current radix, and replace text with
    the new value.

       Notes:     This operator is usually used when calling macros and
                  the value to be passed to the macro is the result of an
                  expression, rather than the actual expression.

                  Text must be a valid expression in the current radix.