The Samsung Sound Bar HW-C450 uses the Samsung IR protocol, device 48.15. It is very likely that your sound bar uses the same protocol. However, the OCAP-4 remote can't send these signals. It is capable of sending the Samsung IR protocol, but it doesn't have a setup code for device 48.15.
The OCAP-4 remote is made by UEI. I don't know of any of their cheap remotes that can control the Samsung Sound Bar, but the UEI setup code is Audio 2609. Of course, you can use a JP1.3 interface cable to add the capability to your remote. Cost is about $20 for the USB to RS232 interface, and 15 minutes to change the connector on the cable from 6 pins in one row to 2 rows of 3. That will match the 6 pin connector in the battery compartment.