>FYI: I've tried looking on the eques website and in their manual. If it's there, I've missed it.

Sure, you did miss it. It's 3rd parameter in SetParams()

lnRetVal = loXFRXobj.SetParams(<tcOutputName>, <tcTempDirectory>, <tlNotOpenViewer>, ;
  <tcCodePage>, <tlSilent>, <tlNewSession>, <tcTarget>, <tcArchive>, ;
  <tlAdditive>, <tlDeleteFileAfter>, <tuAppend>)