I don't know if this is the best way to do it but this is how I figured it out:
1. Save image to your comp
2. Click on manage attachments
3. Upload file
4. Click on linked image (Under current attachments)
5. Copy kennel url address
6. Paste img between
7. To remove the link from your post edit your post go back in to attachments and remove attachment - img should stay put
HTH