How to set an APN as default programmatically?

Hi ,
I am developing an application which creates an APN programmatically by
provisioning the ".Wap-Provisiondoc"
I have successfully created a new network "MyAPN" and it is now showing in
the network setting along with the other networks.
Now i want this network "MyAPN" to be set as default. Because whenever i
want to launch Internet explorer, i want that this "MyAPN" shoould be used
for the network connection.
I think for this i need to make this as default APN.
When ran the query for the "preferredconnections" it shows the operator
network as default. I want to change it to "MyAPN"

I can do this in follwoing two ways
1. By changing the registry settings( I am not sure it will do)
2. I can change the "preferredconnections" under the "CM_Networks"
provisioning document.

I don't know how to do the 2nd approach.
I can add another connection as "preferredconnection" but how to make it
default m not clear.
Please help to resolve this issue.