why can't you copy and paste???
go to your gallery, open up the pic you want to post.. right click on it and select properties. Highlight the URL and right click again.. Select copy.. Come back to your thread or have two pages open (that's what I do) click on the IMG button backspace out the existing
http:// and right click and select 'paste'.. click okay and you're set.
-Matt
by the way, I edited it for you already..