How to set an APN as default programmatically?

I am developing an application for WM 6.0 which needs to change the APN setting
The follwoing steps i have performed
1. Created a new network under "CM_networks" entry into the wap provisioning
XML.
2. Added the GPRS entry corresponding to this network under
"CM_GPRSEntries"into the wap provisioning XML.

Now after this this new entry is showing into the network list alongwith
other network entries.

Now my requirement is that my application which i am developing should be
able to set this new GPRS setting "MyAPN" as default connection
settingsetting.
So that once it is done if user opens the Internet Explorer, connection
should be made by using this setting( as it will be set to default).

I want to know how can my application make it as default?