I'm not sure if I understand the symptoms correctly, but assuming that you can control many functions on the TV using setup code TV 0178, try the following setup codes to try to highlight the menu button:  1423, 1331, 0030, and 1758.

Use  the RCRP05B for the tests.  If a given setup code doesn't corectly send the input command, use the OEM or Atlas remote to get into the menu, and then see if the arrow keys and OK key work using the RCRP05B.

If we find any setup code that can successfully highlight the menu items (and select), even though that setup code doesn't control other TV functions, we'll be able to program the remote to send all the correct signals.

If none of  the setup code can send the cursor functions, then you still have two options. 
1) The RCRP05B is a learning remote, and you can teach the OEM cursor commands to it.

Or,

2) There are only 256 possible remote codes, and we can tell you how to try all 256.