What is the model of the TV that you have? 10812 is the standard Samsung code. You can enter the make & model of the set in question at DIRECTV - Remote Control Code Lookup Now if that does not work, the only other suggestion is to go with a Logitech Harmony remote. You can get the Harmony 200 remote off of Amazon.com, for $45. You are better to get something like the Harmony 650 remote, which is a more robust basic line remote.
Try the lookup link first and go from there. I got tired of dealing with so called provider "Universal" remotes, so ended up going with the Harmony 650.