>>Is there a way to add a new viewer under tools/folder options/files types and configure DDE for it?
>
>You can add handlers to a given file extension by opening up HKEY_CLASSES_ROOT\. file extension; if it exists, it'll point to the name of a handler for the file extension. Under HKEY_CLASSES_ROOT\handler there will be a number of shell entries that specify a verb, the executable to trigger and optionally a DDE directive if the server supports DDE (not all do, or the default may not offer the one you want.)
>
>Your best bet is to follow an existing extension through the registry to see how the keys are built.

Thanks, Ed.
Mark