OK, this was the reply that I got from my webhost:
While we do support .htaccess files, much of the mod_rewrite functionality is not available.
However, you can use Zeus rewrite rules which work in a very similar way. For example, a mod_rewrite rule of:
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^[^/]*\.html$ index.php
Would convert to:
match URL into $ with ^[^\/]*\.html$
if matched then
set URL = index.php
endif
This should be placed in a file named rewrite.script in your web directory.
Bearing in mind that this is the htaccess code that WP generated for me:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
…what do I need to put in the Zeus file? I tried copying their example exactly, but that didn’t work.