What is the code for programming a remote to this TV?

It depends on what brand and model universal remote you are using.

I got the cheapest RCA-brand remote Best Buy had (actually made by Audiovox, who were no help). No code, no scan, nothing worked with this model.
Took it back and got another brand remote (I think it was "Universal"?) suggested by Best Buy's expert on these things (because it has more codes). No luck with that, either.
For good measure, I tried an old Radio Shack universal, and got it to turn off, but nothing further. (That remote predates the TV.) Well, at least I know the sensor seems to be working.
Next and last try is to spend $35-35 for an exact replacement remote for that model.