Request a single file

I’m working on a plugin that will need to call a specific file several thousand times each day. The only thing this file will do is to add a single row into my database.

I have two questions about this.

1) Is it possible to point http://domain.com?id=434 to http://domain.com/wp-content/plugins/pluginname/file.php automatically by adding a plugin? Normally I would use .htaccess for this, but can I make a plugin change in the .htaccess-file when I install a plugin?

2) Which files would I need to include if I only want to get and add some information from the database?

Thanks in advance.