The question is whether AutoCAD can open a file using a WebDAV URL and not a drive letter. So, here is what you need to do to test this. Using IE, go to an entry that has a drawing file attached. Click the button that says "Access Attachments using WebDAV". This will bring up a directory listing of the files in that entyr. Get the WebDAV URL of one of the drawing file. It should look like: http://hostname/ssfs/files/internal/44/1489/attach/simpleFileRepository/filename.dwf.

Take that WebDav URL and open a Dos window on your PC. Then enter the command: "autocad yourwebdavurl" where "autocad" is the name of the drawing program and the url is the WebDAV url of the file. This should open autocad with the file in it. (You may have to play around to figure out the exact syntax to get to Autocad.

If this doesn't work, try doing the same command but use the drive letter and file name syntax instead of the WebDAV URL. If it works using the drive letter and doesn't work using the WebDAV url, then you know that autocad doesn't support opening files using WebDAV directly. If so, then Kablink Edit in place will not work.