About how to create custom php page

[Adem GEN?]

Hello,

I have a php page existing
No problem, working (www.mydomain.com/my_php_page.php)
I want to do with the external php file instead of the plugin.

Example: .com/misc.php?do=page&template=my_php_page such as

Do you have an article? , Can not find the

how do i?

Thanks