One, you are not too old, I would love to be forty again, and two you are not banned from UC or any other college or university forever. It is generally true colleges and universities, both public and private will not accept a student who is not in good standing at their previous schools but case is not typical. First, it has been 15 years since you left UCLA which is a very long time, you have no interest in finishing your degree in Music and a case could be made that your CC, where you are in good academic standing, rather than UCLA is your most recent college.
You could return temporarily to UCLA and do what you need to do to get back in good academic standing while being careful not to complete the requirements for a BA in Music since then you would be applying to schools as a second bachelor's degree candidate to get your Accounting degree and California's public universities will generally not accept such students during this time of very limited resources.
You might also want to expand your target school horizen beyond the UCs Traditionally, UCs have focused on education in Economics and have pretty much left Accounting to the CSUs. I think UCR is the only UC to offer an actual undergraduate degree in Accounting while nearly all of the CSUs do. One thing you have to keep in mind when applying to a CSU is that they have "service areas". If you live in the service area of the CSU with the strongest Accounting Departement, Great, you should get in with no problems. While it varies from CSU to CSU there are some that are all but impossible to get accepted at if you are applying from outside their service area.