Bonita and SharePoint
I'm adding here the information I share in the comment of your other post in case it can be useful to users with the same question.
Bonita now provides a CMIS connector. CMIS is a standard for CMS interoperability and Microsoft SharePoint 2013 support CMIS 1.0.
So you can integrate Bonita with SharePoint using CMIS connector.
For SharePoint 2003 I don't know what the options are but I would recommend to update SharePoint as version 2003 is not supported since April 2014.