Setup ASP FileType To Open In Same MSE Window On Edit

If I right click on a ASP file in Explorer and choose EDIT, Windows
opens a new instance of MSE.EXE and opens the file in that. What I'd
like it to do is simply goto the existing open MSE application and open
the file in a new tab.

I cant find the correct settings to do this is 'FILE TYPES', could
anyone help?

My current settings are (In Explorer: TOOLS > FOLDER OPTIONS > FILE
TYPES > ASP FILE > ADVANCED > EDIT > EDIT):

Action: &Edit
Application used to perform this action: "C:\Program Files\Microsoft
Office\OFFICE11\MSE7.EXE" %1
Use DDE: Ticked
DDE Message:
Application: MSE7
DDE Application Not running:
Topic: System


TIA,

Colin