custom php script in admincp

[regitbull]

Hello,

I followed a few vbulletin tutorials to show a custom php page in the admincp.
I found out that anyone can just access the php file located in my admincp without the need to be a admin or even be a forum member.
I think because my php page is just white and not blue as normal it just shows the php file in admincp but isint linked to the admincp at all.

Could you guys tell me or show me a link explaining how i can add a custom php page to the admincp.
Or use a plugin to add the php code there and make a page in admincp show this php code.

Im a bit stuck and cant realy find info anywhere how this is done.

The php page i want to show is just a simple php file with a form that connects to the mysql database and runs a query to edit a vbulletin table.
I just want to make this form with 2 text fields show in the admincp so only admins can run this query script.

thx for any help.