Microsoft has a
SQL Server 2000 for the Sybase Customer Resource Kit
http://www.microsoft.com/sql/evaluation/compare/sybaseresourcekit.asp
also, see
Chapter 6 - Migrating Sybase Databases to SQL Server 2000
http://www.microsoft.com/TechNet/prodtechnol/sql/reskit/sql2000/part2/c0661.asp?frame=true