I have to agree to XrAy on this: even though there are ingen�ous ways to "massage" the system to do whatever, like the one rbatte1 has provided, it is generally better to use the provided utilities. This sometimes helps and never hurts.
It is good to know these workarounds (if for no other reason than to know your system better), so i think there is value in rbatte1's contribution, but one should stick to the supported methods as long as possible at any rate. (For the same reason, i.e., i would always use "chinet" to modify lasting routing entries instead of using "route" and then patch them into the ODM, even if i might succeed in doing so.)