Plugin with PHP

Hi,

How it's possible to make a plugin wich open a dialog box and load a php file into this dialog box.

I mean like it is in FCKeditor:

FCKCommands.RegisterCommand(
   'Innerlinks',
   new FCKDialogCommand(
      'Innerlinks',
      CKLang.InnerlinksDlgTitle,
      '../../../util/innerLinks.php', 520, 650
   )
);

This code open innerLinks.php in a dialog box and all the code is in php.