Credential Provider for Windows 7 in C++

I need the following functionality: Credential Provider for Windows 7 which contains a link to reset password at the logon screen. When the user clicks the link we would prefer if it could execute and load a windows forms application written in .net. My company can write the windows form itself, but we need advice if this is possible or if it should be written in C++? Can an external application be called to provide both the username and password to the credential provider so that the credential provider automatically can log on? We need code that has been tested and that is stable. :) Looking forward to hear from you.