Outside database, including WP elements

Hi, I have created a webpage that uses a non-WP database to display some data. I would like to then use some of the WP elements to style the page to make it fit with the rest of the site. (I tried to insert the page into WP but I couldn’t get it to work right…) I have added the wp-blog-header and I am getting the sidebar like I want, but now the original database elements don’t work. I think the call to the WP database is overriding my other database? Is there a way to make them work together?