Configure Remote Codes for a Video Source on Slingbox 500

[tvpat]

Is there any way to define new remote keys for a video source? It used to be done using SlingPlayer Desktop. You would configure a video source and define its remote.

Here is a document that describes the process.
How to Install a Custom Remote onto the Slingbox.pdf

That process no longer works because SlingPlayer Desktop flips to an invalid url.

When you connect to a Slingbox that has remote codes configured you get a message on the server that Keycodes have been loaded. Here is an example for a DirecTV remote:
dtv Keycodes= [1, 2, 4, 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 24, 25, 26, 27, 28, 29, 30, 31, 33, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 62, 63, 64, 65, 66, 67, 68, 69]

If no keycodes are configured for that video source you get the following message:
dtv Warning: No remote keys configured, using correct VideoSource?

Is there any way to still do this for a Slingbox 500?