i took the liberty of modifying an account reg script for you
upon create the account will have a gm rank of "3"
if you would like to change this rank to something else (ie. 'az')
on line 32 you will find this
Code:
$sql = "INSERT INTO accounts(login,password,encrypted_password,gm,email,flags,lastip) VALUES('$login','$password','$sha1pass',3,'$email',24,'$ip');";
change the bold 3 to whatever rank you want and your done 
ps. dont forget to modify the config file ^_^
Here you go
GmRegPage
if the page doesnt work tell me and ill work up another one