No problemo mon!
Two things -- you were close. First, link to the picture itself, not the page that displays the picture. I.e., right click on the photograph, select "copy image location" (or "properties" depending on what browser you use). (Mac users, I know you can't right-click, but there must be some way of displaying the image properties ..). Second, the image will have some sort of number following the file extension. I have no idea what this is, maybe it's some of sorting number used by the board's software. You need to trim this off. Sounds complicated I know but it's not that bad once you've done it once or twice.
HTH.