[sino1232003 (OP)]

Please check the Subject of the forum under sino1232003
"How to claculate Alt-az Tracking star Urgent need"

[gsmollin]

This answer is pretty detailed, and even though I think I could work it out, I'm not inclined to write the engine for your telescope tracking program. You will, unfortunately, either have to research it yourself, or hire an astrophysicist to give you the answer.