It won't appear by itself. The link it's just the URL that takes us to your blog.
If you want to have your blog/text/writing On the forum, you have to
1.Select the text on your blog
2.Click on the right button of your mouse, select 'copy'
3. Then you come to the forum when you have your 'reply' window in your blog-thread
4. You place the cursor in the text section of the post, click the right button of your mouse and select 'paste' -
that's what we mean by 'copy-paste' - which is copying the text from your blog to the forum.
Otherwise it won't appear just by placing the link.
So, just like you copy paste the link, you can select the text - this is dragging your mouse while clicking covering all your text, and pasting it on your reply-post as usual.
Let us know if that clarifies the point.