Sorry if bumping is not allowed, I just had an idea I felt would be nice to put out.
I think the idea argv provided, by evaluating things within {}'s, can be implemented by something like:

alias set2 { 
  var %a $iif($left($1,1) == -,$2,$1), %b $iif($left($1,1) == -,$3-,$2-)
  set $regsubex(%a,/\{(.+?)\}/gi,$(\1,2)) %b

An example could be:

/set2 %b.{$chan}.{$me} Foo Fahhh
might set %b.#mirc.Firstmate to Foo Fahh