I don’t know too much about this forum yet so there may be other ways of linking to other topics, but I made this link by surrounding the url with < url> < url> tags, I’ve added spaces to these tags to make them show.
< url>Making an elbow piece - #2 by Cotty< /url>
Without the spaces results in the link bellow, though strangely the link seems to work even with the spaces in the tags.