write from existing db into wp db

Hi

I got an existing mysql db which already has many postings in it (title, article, author and 3 user fields). How do I go about writing all these into the wp db? I looked into post-by-mail (i.e. write a php script which generates many emails) but didn’t know how I could get the 3 user fields entered as well.

Would be great if someone could help.

Many thanks
hawpnk