Thank you all for your responses!!
@ Terjeio,
I am using C and the value I need to store in split registers so that when I connect a synthesizer I can feed the value to it for further actions. I am not sure if the value is stored in stack memory will I be able to retrieve it later as the compiler stores at random address?? Therefore i thought of storing it in registers of the MSP430 so that i can access the value for later purpose.
As #Agaelema mentioned I used a pointer to receive the address of the 64bit variable and increment it to read all the address.