Claro ke si lo puedes hacer yo lo hice con movistar peru y un cda generico para despersonalizarlo.
Lo editas y agregas cuentas de internet , mensajes multimedia , etc . ejemplo :
<internet>
<account modifiable="false" account-type="ps">
<name>Internet Movil</name>
<username>movistar@wap</username>
<password>movistar</password>
<prompt-password>false</prompt-password>
<apn>wap.movistar.pe</apn>
<service-mode>automatic</service-mode>
...
</account>
<account modifiable="false" account-type="ps">
<name>movistar MMS</name>
<username>movistar@mms</username>
...
</account>
</internet>
Son 3 cuentas en este caso.
<mms>
<settings reg-path="/apps/msg/mms">
<request-read-report>false</request-read-report>
<request-delivery-report>false</request-delivery-report>
<send-read-report type="str">confirm</send-read-report>
<validity-period type="str">maximum</validity-period>
<reject-advertisement>false</reject-advertisement>
<reject-anonymous>false</reject-anonymous>
<message-max-size>300</message-max-size>
<download-home type="str">confirm</download-home>
<download-roaming type="str">confirm</download-roaming>
<content-creation-mode-visibility>0</content-creation-mode-visibility>
<content-creation-mode type="str">free</content-creation-mode>
<resize-picture-mode type="str">standard</resize-picture-mode>
<max-number-of-recipients>50</max-number-of-recipients>
<message-max-video-size>300</message-max-video-size>
<active-account>1</active-account>
<account-list>
<account id="1">
<name type="wstr">Movistar MMS</name>
<message-server type="str">http://mmsc.telefonicamovistar.com.pe:8088/mms/</message-server>
<netw-account type="wstr">movistar MMS</netw-account>
</account>
</account-list>
</settings>
</mms>
Esto tambien le agregas ... pero el de tu pais.
Y esto tambien ..
<dcom>
<settings reg-path="/apps/dcom">
<apn-restriction>
<enable>false</enable>
</apn-restriction>
<proxy-list>
<proxy id="1">
<name type="wstr">Internet Movil</name>
<address type="wstr">200.4.196.117</address>
<account-name type="wstr">Internet Movil</account-name>
<port>8080</port>
<type type="str">HTTP</type>
<enabled>true</enabled>
</proxy>
<proxy id="2">
<name type="wstr">movistar MMS</name>
<address type="wstr">200.4.196.118</address>
<account-name type="wstr">movistar MMS</account-name>
<port>8080</port>
<type type="str">HTTP</type>
<enabled>true</enabled>
</proxy>
</proxy-list>
<account-list>
<account id="1">
<name type="wstr">Internet Movil</name>
<homepage-title type="wstr">Internet Movil</homepage-title>
<homepage-url type="wstr">http://www.movistar.com.pe/emocion/homepage.html</homepage-url>
</account>
<account id="2">
<name type="wstr">Internet</name>
<homepage-title type="wstr">Sony Ericsson</homepage-title>
<homepage-url type="wstr">http://wap.sonyericsson.com</homepage-url>
</account>
<account id="3">
<name type="wstr">movistar MMS</name>
<homepage-title type="wstr">Sony Ericsson</homepage-title>
<homepage-url type="wstr">http://wap.sonyericsson.com</homepage-url>
</account>
</account-list>
</settings>
</dcom>
Aun asi lee bien todo el custom de tu pais y extrae la informacion necesaria comparandola con el custom generico que le pusiste a tu cel.
Suerte.