You can use the suggestions you've got above to do this. However, if the HTML is under your control, I'd strongly suggest you look at fixing it so that it works consistently between IE and NN. This really shouldn't be that hard (unless you're a masochist and trying to support very old v4 browsers), especially if you get browsers to parse your page in 'Strict' mode by using the appropriate DTD.

Keep It Simple: the more things that have to happen from a browser requesting a page to the server sending it back, the more things that can go wrong. Serving flat HTML files is simple. Having client-side code call a CGI, rewrite an (arbitrary?) file is fiddly, fragile, harder to maintain, consumes more server resources and slower.

If you really can't manage to get consistency using HTML & CSS, see if you can at least handle the inconsistency purely on the client-side using Javascript.

Cheers
ViceRaid