argument to specify midi port

at the moment, i have one window in which to specify which midi port to use, then send that info out to a number of devices scattered around.

so, rather than send the midi port number all overer.
can i assign it a particular argument that i can then use automatically ??

my first thoughts with ports a-z, was that i could assign any specific port to "a" for example, then all using the "a" argument would be attached to that particular port.

thanks.