Certificate Template: create Custom OID

Hi,

I need to create certificates with a Custom OID. The only way I found is to modify the certificate template (User) and to add it to to the Application Policies as explained here: 

1. On the Extensions tab, click Application Policies, and then click Edit.

2. In the Edit Application Policies Extension dialog box, click Add.

3. In Add Application Policy, ensure that the application you are creating does not exist, and then click New.

4. In the New Application Policy dialog box, provide the name for the new application policy, note the generated object identifier, and then click OK.

In this way my OID will be under X509v3 Extended Key Usage.

Is it possible to create this OID under the x509v3 extensions directly (not as a child of Extended Key Usage) in the form of a key value pair? Ex: my_oid : my_custom_string

Regards, Antonio