In a simple HTML it could work like this:

<a name="oldPost1"></a>
Your old post /paragraph here ... put more test to see how it links to this
<a href="#oldPost1" title='few details about the old post'> link to old post 1/paragraph </a>
If you want to link to another page, the href should look like this:
<a href="http://yousite/anotherPage#oldPost1" title='few details about the old post'> link to old post 1/paragraph </a>
That means:
Add the <a name="oldPost1"></a> before the paragraph.

put the link like this to your old marked post (it should work from any page):
<a href="http://www.burntmouth.com/index.html#oldPost1>link</a>

All best,
Radu