I do not take full credit for this script, it was made by my friend and me.

Execute PHP in mIRC Without any DLL's

• $php(option,arg)

  -- $php(eval,argument)
  -- $php(check,argument)

• /php Option Argument
  -- /php eval argument
  -- /php check argument
  -- /php function argument

*** CHANGE phpexedir TO THE PATH OF YOUR PHP.EXE!!!

Includes a leveled command as an example.
$level($nick) - Level of the user in Users In the script editor

= Every level higher than 4 or equal to 4

alias phpexedir { return C:\php\php.exe }

alias php {
  var %b CreateObject("WScript.Shell").Run "cmd /c $phpexedir $replace($1,Eval,-e temp.php,Check,-l temp.php,Function,--rf $remove($2-,shutdown,restart,exit,quit)) > temp",0,true,%r .remove temp
  if ($1 == eval || $1 == check) { write -c temp.php <?php $crlf $2- $crlf ?> }
  elseif $1 != Function {
    $iif($isid,return,echo $color(info) * Error: $!php) $chr(32) $+ *** Wrong Syntax!. $!1 arg must be eval, check or function
    halt
  }
  .comopen c MSScriptControl.ScriptControl
  .comclose c $com(c,Language,4,bstr,VBScript) $com(c,ExecuteStatement,3,bstr,%b)
  if (!$file(temp).size) write -c temp *** Script returned errors, please check it.
  if $isid {
    bread temp 0 $file(temp).size &b
    %r $+ .php
    %r
    return $bvar(&b,1-).text
  }
  else .play -es temp 0
  %r $+ .php
  %r
}
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Example of what can be done:
;;
;; <Brandon> \eval echo("wut");
;; <Bot> Return: wut
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
on *:TEXT:\eval*:#:{ 
  if ($level($nick) >= 4) {
    if (shutdown isin $2-) { .msg $chan *** Error: You cannot use this command [Filtered] }
    elseif (restart isin $2-) { .msg $chan *** Error: You cannot use this command [Filtered] }
    elseif (exec isin $2-) { .msg $chan *** Error: You cannot use this command [Filtered] }
    elseif (spy isin $2-) { .msg $chan *** Error: You cannot use this command [Filtered] }
    else {
      .msg $chan Return: $php(eval,$remove($2-,shutdown,restart,exit,quit,spy,exec))
    }
    else { 
      .msg $chan *** Error: You do not have enough access to execute this command.
    }
}