The UR5-8400 only uses 3 digit codes for input on programming. That 3 digit code is the file for the IR database built into the remote.
File codes for other remotes are not going to work on a different remote. Understanding the above should help understand why that is.
There are 7 code sets for Sony audio receivers in the UR5-8400 database (001, 011, 055, 187, 053, 112, 205). I would say the odds are extremely high, one of those code sets will control your Sony audio receiver.
Here is the manual, all the info is there:
[Link: timewarnercable.com]