You would like to index documents stores on a remote SharePoint and would like to learn whether it is possible.

You can index documents stored on a remote SharePoint 2007 or 2010 server using WebDAV. Once you have enabled WebDAV for SharePoint, you can use the "Remote SMB Share" option available during IDM index configuration to index the remote documents.

For details on implementing the feature refer to the link provided below:

Using the remote SMB share option to index SharePoint documents (broadcom.com)