You can make a screenshot yourself by following these steps:
0) If you're currently playing the fort, generate the world again with that parameter set.
0.5) Alternatively, copy your world folder, go to the copy, abandon.
1) Find the spot where your fortress was. Press alt-prt sc, which copies an image of the current window. Make sure the blinking yellow x's are visible when you do this.
2) Open MS Paint or another image editor. Paste the screenshot. Save it as a .png file (i.e. thisismyfilename.png). .jpg files are too fuzzy, don't use them for DF screenshots or simple pictures. .bmp files are too large, don't use them for anything.
3) Go to an image host website; the most frequently used ones are Photobucket, Imageshack, and Tinypic (google any of those words to find it). Photobucket is good for long-term storage, but Tinypic might be easier to use.
4) Upload your screenshot there. You'll get a set of links. Copy the IMG link and paste it in a reply on this forum (if it's large, you may want to put it in spoiler tags).
If your image is shrunken or the host doesn't have an IMG link, copy/paste the direct link instead (if it doesn't say "direct link," it's probably not a direct link) and put it inside IMG tags (if that confuses you, there's a button above the reply box here that'll do that for you).
If the host doesn't offer a direct link either, use Tinypic or Photobucket, they have one.