Thanks for your reply.
It has nothing to do with hardware setting. It is the SlingPlayer software that forbids me to select the Hong Kong Region (NOW TV) remote. The streaming is working perfectly, just the remote input is not allowed after the end of Feb.
Anyway, I have packed the slingbox into the box for now as my home is doing major renovation. I have read some other manual remote code from forums and will try the out when I have my home back.