How do I use "Link to current document"

Apparently I don’t understand how to use the “Link to current document” script. I’m trying to include a reference in my DTPro database back to a specific PowerPoint presentation. I’ve tried just opening the presentation and invoking the script, but I just get a dialog box with the error message “No document is open”. So I created a new RTF document in DTPro, went back to the presentation, invoked the script but still got the same message. Can anyone provide some clarity for me?
Thanks

Scripting is usually application-specific and therefore this script uses a generic approach. Most scriptable Cocoa applications for example should be supported but many Carbon applications (like MS Office) aren’t.

But you don’t need the script to add the file to your database of course, just use File > Index or Command-Option drag & drop.

As I mentioned in my original note, I’m trying to establish a reference to a PowerPoint file (which, interestingly, is mentioned as an example of what the “Link to Current Document” script is supposed to support). Using either the File>Index or command-option yields nothing (just a sound, in the latter case).

Just enable the import of unknown filetypes (see Preferences > Import).

That did the trick.
Thanks

A useful and simple alternative to importing a PowerPoint presentation into the database as an unknown file type, is to first output it as a PDF and then import the pdf into the database, rather than the PowerPoint “.ppt” file [1) open file in PowerPoint, 2) File Print, Save as PDF, 3) import or drag PDF file into database]. This creates a text searchable PDF of the original PowerPoint presentation within the DEVONthink database.

Some complex presentations might not work well (though I haven’t had one yet). But I have used this method for numerous PowerPoint and KeyNote presentations. The result is a richer, searchable, more flexible database integrated with the PowerPoint/KeyNote material.

Note that I do not have to be concerned with opening an external application just to view the document content. I can quickly view and navigate through it within DEVONthink. Backing up is easier since the document is now contained within the database.

If I did require a link to the original file, I can still have that too (just import as unknown file type).