It has been suggested in the past, try the Search feature. Online also made a snippet using COM, which can be found here. Be sure to read the documentation that comes with it.

A slightly modified version of it would be:

Code:
alias sleep {
  var %a = $ticks $+ .vbs
  write %a WScript.Sleep $$1
  .comopen %a WScript.Shell
  if !$comerr { .comclose %a $com(%a,Run,3,bstr,%a,uint,0,bool,true) }
  .remove %a
}


The N stands for the amount of milliseconds.

Btw Online, if you are reading this: I'm curious why you use jscript and a .wsf file. Is there an advantage over vbscript?

Greets