I seriously advise you to throw this so-called HTML away, shoot the author, and rewrite it (from scratch or using a perl-script). Step 3 is optional; steps 1 and 2 are not.

I have seen many projects of exactly this sort. they never turn out to be worthwhile; the HTML is always worse than anybody has any reason to expect. every pattern you think you see will be broken, except this one: they will constantly find new and creative ways to abuse the HTML. they will forget to close tables. they will left jsutify and right justify the same paragraph. they will nest comments. (nesting comments, (or fails to work) --> like this). They will even use the blink tag.

trust me. let the bad html flow out of your database and out of your life. you don't want it. it is faster to retype it properly than to "fix" that mess. my mother was given a free car once. it's the most expensive car she's ever owned. she buys them now. it's cheaper.