Check for Running Instance of an application

[rruble88]

Hi,
I'm trying to keep from running multiple instances of the rundll32.exe (open with dialog.). I've read alot of topics on the forum and they all seem to be about app.prevInstance, but can't find one dealing with outside applications. Can anybody point me in the right direction? Thanks alot, Rick

Shell ("rundll32.exe shell32.dll,OpenAs_RunDLL " & strFullName)