In this case, it could be better to change it too.
Code:
ASM
NOP?C   macro Cin
    local a
a=0
    while a<(Cin+MyByte)
        nop
a++=1
        endw
    endm
ENDASM
and at the top of your code you define MyByte like
Code:
@MyByte=.10 ; your value.. whatever