este cod te permitira trabajar con subdominios y wildcards es muy facil de configurar
<?php
#####################################################################
# Subdomains 0,51
# Released under the terms of the GNU General Public License.
# Please refer to the README file for more information.
#####################################################################
#####################################################################
# PLEASE EDIT THE FOLLOWING VARIABLES:
#####################################################################
# Your domain name. NO "www." IN FRONT OF IT. NO SLASHES ("/"). - Tu dominio no debe contener "www" y tampoco "/"
# Just the actual domain name, i.e. "yourdomain.com" - Coloca el dominio en el cual tienes el script
$domain = "yourdomain.com";
# The default page that the visitors should be redirected to if - al entrar en la pagina default seran redirigidos a la correcta
# they don't request a sub domain or they request a non-existing
# sub domain. This page could be named "welcome.html",
# "front_page.html" or something similar. The page should be
# located in your document root. If you can view the page by
# entering "http://yourdomain.com/welcome.html" in your browser,
# then it is located in the document root.
$default_page = "welcome.html";
# Do you want to use frames?
$use_frames = "yes";
#####################################################################
# THAT'S IT! NO MORE EDITING NECESSARY. - No necesitas modificar nada despuees de aqui
#####################################################################
$underdomaene = $HTTP_HOST;
$underdomaene = eregi_replace(".".$domain, "", $underdomaene);
$underdomaene = eregi_replace("www.", "", $underdomaene);
$underdomaene = strtolower($underdomaene);
# If the sub domain is the name of a directory in the document root...
if (is_dir("$DOCUMENT_ROOT/$underdomaene")) {
# The frames version:
if ($use_frames == "yes") {
echo "<html><head><title>$domain/$underdomaene</title>nn";
echo "<!---------------------------------------------------------------------n";
echo " The sub domains at $domain were created usingn";
echo " the PHP script "Subdomains"n";
echo "---------------------------------------------------------------------->nn";
echo "</head>nnnn";
echo "<frameset cols=100%,* frameborder=no border=0 framespacing=0>n";
echo "<frame src=http://$domain/$underdomaene>n";
echo "<noframes>n";
echo "<body bgcolor=black link=silver alink=black vlink=gray>n";
echo "<font face=helvetica color=white><center>n";
echo "This page uses frames, but it seems that your browser does not support this feature.n";
echo "To move on, click here:<br><a href=http://$domain/$underdomaene>$domain/$underdomaene</a>n";
echo "</center></font>n";
echo "</body>n";
echo "</noframes>n";
echo "</frameset></html>n";
}
# The non-frames version:
else {
header("Location: http://$domain/$underdomaene");
}
}
# If the sub domain is NOT the name of a directory in the document root...
else {
if (!$REQUEST_URI || $REQUEST_URI == "/") {
include("$DOCUMENT_ROOT/$default_page");
}
else {
header("Location: http://$domain$REQUEST_URI");
}
}
?>