Hi,
Is there a special reason for you to build it as a DLL? I would suggest that you build it as an exe and launch it, controll it and communicate data through ActiveX. Witht his method your applications can work independently and you have them running in diferent tasks. I've never attempted to do a DLL with a UI that communicates throuhg ActiveX, but sounds possible!
Just my 2 cents; hope that helps.
Juan Carlos
N.I.