The below link has constants for SQL Server 2000 and not SQL Server 2008 R2. Do you have a link for SQL Server 2008 R2?
http://technet.microsoft.com/en-us/library/aa902635(v=SQL.80).aspx
For example, REPOLE_SERVER_MINOR_VERSION has information for only SQL Server 2000.
Here is example code, http://www.replicationanswers.com/CustomResolver.asp. Do you have others online.
Thanks,