Parsing bad HTML

I use tidy to clean up  bad html docs. It does a pretty good job of converting html => strict xthml

However, the following is a bit too much

<p>
₁₂₃4567<eight<img src="file.gif" alt="<b>hello</b>">
</p>

The problem is with 7<eight. Stray < and > seem to make tidy choke. What is the best method of handling this? I am leaning toward perl and regexp, but am hoping to avoid this. Maybe a Java solution? And tidy solutions?

-thanks