This is not possible, because websites cannot link to the files on your computer. This would be really bad!
You always need to upload the files to a web server. I could allow to upload files to the forum, but this would mean tons of MB... and as you already know from the old gallery my space is limited ;). That's why I cannot do this. The only pictures you are allowed to upload here are SP-Studio related pictures to your user gallery.
But there are many ways how to get your file online. You can upload it at Facebook or Google+ if you have an account there and then link to it. Or you can use your own webspace if you have any. If you don't have anything like this there are free services which offer space for image files. Here are two of them:
http://imageshack.us/ (you need to regsiter your e-mail address)
- Choose the image file from your computer ("browse" button).
- choose "resize for message boards, 640x480 pixel".
- click the "Upload now" button
- Copy "forum code" and paste it into your post.
http://www.abload.de/ (no registration, but in German)
- Choose the image file from your computer ("Bilder von der Festplatte hinzufügen").
- choose "verkleinern" > "lange Seite 600pixel".
- click the "Abload!" button
- Copy "Code für Foren" and paste it into your post.
Give it a try, websites like this are easy to use :).