Webservice end point in case of SFDC Sandbox in Datastore?

Hi Experts,

I am currently working on BODS 4.1 . I am trying to  create a datastore of Adapter type for SFDC .

I have the user name ,password and passtoken for SFDC sandbox(test.salesforce.com).

what would be the webservice end point ,to be passed in datastore defination as by default it is https://www.salesforce.com/services/Soap/u/21.0

But in case of //test.salesforce.com (Sandbox SFDC) ,waht would be the value of Webservice end point.,as it is not allowing me to create the datastore with default web service end point.

Any help is appreciated.

Thanks & Regards,

Mayank