I’m afraid with the suggested solution you wont be able to pull the full name from the CMS, but you can pull the description field.
The possible methods you can use are listed here:
http://devlibrary.businessobjects.com/BusinessObjectsXI/en/en/BOE_SDK/boesdk_java_api_doc/doc/boesdk_java_apiRef/com/crystaldecisions/sdk/occa/security/IUserInfo.html
Other than that, have a look at the discussion on Change Display of User name to Account Name (XI R2)
Orange 
(BOB member since 2006-09-18)