Connection to R/3 from EP6.0 (using different user id)

Hello I am trying to connect to R/3 from portal.

The code I have written fot this is following and it works fine.

-

IConnectorGatewayService cgService =

(IConnectorGatewayService) PortalRuntime.getRuntimeResources()

.getService(

IConnectorService.KEY);

ConnectionProperties prop =

new ConnectionProperties(

request.getLocale(),

request.getUser());

return cgService.getConnection(alias, prop);

-

Now in this code, the user is always the user which has logged in to the Portal.

Is it possible to specify a user id in the code.

I want to log in to SAP using a specific user id.

Any help will be greatly appreciated.

Regards, Sanjeev Srivastava