Hello Louise, Maybe this will help.
From Nov/64 to May/65 the Reserve Corps in the District of Arkansas was placed under the control of Thomas Pleasant Dockery. Since Flippin was a commander of Reserve Cavalry, that would be your chain of command for those six months.
Dockery is footnoted in a book I just read, "I acted from Principle". The footnote reads: Anne Bailey, "Thomas Pleasant Dockery" in 'Confederate General', 2:70-71.