You can use the Microsoft Cryptographic Service Provider Developer's Kit (CSPDK) to sign and test your own CSP. In accordance with the U.S. Department of Commerce's export restrictions concerning cryptography, Microsoft must digitally sign a CSP so that it will run on Microsoft operating systems. In addition, Microsoft can only distribute the CSPDK to legal residents of North America (U.S. and Canada). While you can submit final versions of CSPs to 'cspsign@microsoft.com' for signing, the CSPDK allows you to test the CSP before you submit it to Microsoft.
For more information on how to obtain the CSPDK, point your browser to http://www.microsoft.com/security/tech/cryptoapi/cspdkintrocontent.asp.