I'm not doing this as a part of my job. And I'm not even considering developing "my own CMS". If you look into my post, you will see that the task is limited. I don't like to reinvent wheels, but I don't want to use a lawn mower, where simple scissors would do.
If you know about anything that's already available, that won't require modifications to the existing site, and will work with a host that does not support Perl / PHP / other, I will be very grateful for some suggestions. I already mentioned Unify, but this solution requires PHP support, and, although I'd be willing to pay for the software out of my own pocket, I'm not paying the annual hosting cost, and I must consider that the site owner won't like any upgrades.