Import from custom PHP/MySQL blog application

Hello,

I have a blog application, (for lack of a better term,) that I wrote several years ago using PHP and MySQL. The system is old now and better systems (like WordPress) are being produced, so I thought that rather than trying to support and extend my system, I would try this out and see if I liked it, with the possibility to extend WP installs to all the other installations of my custom app.

So I have a few questions.

First, I was wondering how difficult it would be to import the content. The content is stored in HTML. Is there a resource I can use to build an import script?

Second, my system has the ability to add additional information to each post which is password protected. These are generally personal comments about the info in the post that are made available to a select group of readers. Does WordPress do anything like this? So far, I’ve only noticed the ability to protect entire posts. But I’m still new.

Any help is appreciated.