Is this possible? If so, what would the syntax be? %mn is not a control, per se, because I tried:
i = winio@('%mn[help[help]]%ud&',button1,15)
And it threw a run-time error about the %ud not being used with a control.
/CHECK_WINIO does not pick up this syntax as an error. It might be too infrequently possible that it's not worth trying to include it, but I did try it!