I wasn't able to find anything specific, however, depending on what you're wanting to do, this might be informative.
When I put a dialog command into a menu, I check to see if the dialog is already open or not. If it isn't open, then I use the -md switches, however, if it is open, then I use the -ev switches (which restore the dialog and make it active).
The general format in the menu looks like this
Code:
menu * {
  dialog $iif(!$dialog(name),-md,-ev) name name
}

Hope this is of some assistance.