encrypting appSettings in a external file using aspnet_regii

Question

I am trying to encrypting appSettings in a external file using aspnet_regiis -pef. Does anyone how how to do this.

 

My main web config file :

<appSettings file="ExternalAppSettings.config">

<add key="test1" value="val1" />

<add key="test2" value="val2" />

</appSettings>

 

 

external file ExternalAppSettings.config

 

<appSettings>

<add key="pwd1" value="test1" />

<add key="pwd2" value="test2" />

</appSettings>

 

I want to encrypt only appsetting in ExternalAppSettings.config how to do this ?