POST from an tag

Not really, no. You can, however, do something like this:

<form action="theUrl" method="POST">

<input type="hidden" name="param1" value="val" />
<input type="hidden" name="param2" value="val2" />

<a href="#" onclick="this.parentNode.submit()">Go to that link!</a>

</form>

You should find a better way, though. This one does not degrade gracefully.