It turns out that mod_rewrite doesn't really work with PHP-CGI... which of course is how my server is configured. I could turn that off, but then I'd have horrible security problems. Or I could do something really freaky with rewriting to a non-existant dummy file handler, but frankly...
Arrghhh!
If none of the above makes any sense, pray that this continues to be the case for you. As Vinay puts it, regular expressions are straight out of the realm of Satan.
hrm. well, what I do is this:
RewriteRule [match] redirect.php
Just analyse the URL in redirect.php and then do a redirect at that level, no? OOOgly, but it works. If you want to skip the redirect part, then do
?
if (stuff on the SERVER[REQUESTURI] variable) { set parameters include (“file which does the work”) }
repeat for as many clauses as necessary.