command line parameters for IEXPLORE.EXE

We are attempting to programmaticaly open a web browser from a DOS based app in our company intranet. We have been successful in this regard except that each each time the DOS app. performs this open, it opens IE in a new process disallowing access to any session vars (on the web server) that may already have been set. The end result is a grossly inefficient system.

The question: Are there command line switches that would tell IE to use an existing process? If not, is there a way (in a DOS environment, mind you) to query the PID of a currently running instance of IE and open a URL with it.

(Sorry if my terminology is off: the perils of being self taught….)