having a marker of some sort, such as a special variable name, requires access to the files to place it there...
what I'm intending is to automate a setup script where I do not have access to the mirc environment at all, so there is no way to do this.
I have worked out a way to make the additions without first knowing if a file is loaded... took a few hours of experimentation to work out the procedure, but so far it seems pretty bulletproof.