I am an HR manager I must uphold laws that protect transgender rights. As a Christian can I do that?
"Therefore, whatever you want men to do to you, do also to them, for this is the Law and the Prophets" (Matthew 7:12).
As best that I can tell, the laws bascially demand that people be treated the same regardless of their religion, what they look like, or what sexual sins in which they may be involved. While a Christian disagrees with a man living with his girlfriend, he can still hire the fornicator to do a job for a company. Transgenderism should be treated no differently. Yes, the person makes the false assumption that if he pretends to be a different gender that he will be happier, but it shouldn't make a difference whether he can perform a job or not.