Storing certificates into Trusted Root Certification Authority programmatically

Hi All,
I have a client certificate(.pfx PKCS12 file) and I want to
put that in Trusted Root Certification Authority. I can always right
click on certificate and say install, but I want to do that in
programmatic way. How can do this programmatically ? I tried
overriding RemoteCertificateValidationCallback
(CertificateValidationCallback), that seemed to work for allowing
client's certificate on server(by returning true), but this is not
working in same way for allowing server's certificate on Client side,
just by returning true from that callback routine in client program.
Still it say remote i.e. server's certificate is null.

Thanks in advance,