Can anyone tell me whether I can program my Fios Remote to operate volume on an LG Soundbar I am thinking of buying.
It depends on the remote you have. Some control only 2 devices, some control 4. The following link will give you info on each Verizon remote control. http://www.verizon.com/Support/Residential/TV/FiOSTV/Remote+Controls/SetUp/SetUp.htm
Or you can check out third party remote controls that have more capabilities. The Harmony seems to be one of the most popular, but I have not used it myself. A forum search for "Harmony remote" will return threads that discuss it.