pretabulated modulation of variables

i want to use x2 adruino 11 controllers ( im noob to programming, better than noob to physics btw) one of which acts as a digital signal propagator and the other has been programmed to have it's analogue input displayed in a PC interface eqiuvalent to an ocilloscope called "simplot" which i downloaded from the creator's website, much graditude must be given to this individual by anyone using this program as the creator had the humility and compassion to upload the relavent code for people like me who are new to code. i have learned much from you sir.

I digress, i wish to know how i can instruct the microcontrollers to periodically read instructions from a excel or XML, tab delimited does not really matter to me, some kind of file storable in the small amount of memory available in the MC as such that redefines the variables in the it's primary code.