set %welcomemsg. [ $+ [ $chan ] ] $rand(1,99)
notice $nick %welcomemsg. [ $+ [ $chan ] ]
Not sure what you wanted that "test" in there for. The way it is now, it'll send you a notice with a random number, the word test, and another random number. You can call back that first variable by referring to it as %welcomemsg. [ $+ [ $chan ] ]
-Correction- I had the test thing on the same line as the welcome message variable. The test line won't do anything now. If that's not what you want to do, just let me know.