Iam really surprised that it does not exist. though iam not sure if my surprise is really a surprise for joomla/cb or not because iam just an end user of joomla, i do not know its core working.
having mentioned in registration form that you will get an validation email, i dont know how many of them will actually try logging in, without getting the validation email. instead they will come back and try to look for activation resend link..
so no help in this.. ok great.
thanks all.