If you, as you just mentioned, are trying to put it into a page (or post), you should use the shortcode. The shortcode can also be found on the slideshow settings page. The piece of PHP code can only be used in your theme's PHP files.
If you're already doing this correctly, yet nothing's showing up, it could be that 4200 is not the ID of the slideshow. Version 2.1.16 will fix the issue with using non-existent ID's and will probably be released tomorrow.
Otherwise, could you put the code on your page again and point me to the page you're trying to place the slideshow? I wasn't able to find the page you were trying this on.