Excel formulas /Calculator for Grains Per Pound/ Grain Depression

My dehumidifier gives me the following readings which must be recorded daily. Temperature in, relative humidity in, temperature out, relative humidity out. Currently i am using a psychrometric calculator by SYCORP calc Pro. After i enter this data, it spits out Vapor Pressure In, Vapor Pressure Out, Grains Per Pound In, Grains Per Pound out, Grain Depression (GPP in minus GPP out), Dew Point In, Dew Point out. I have a lot of these to do and I would like to automate the process. The most important is the Grains Per Pound In, Grains Per Pound out, Grain Depression (GPP in minus GPP out). I would LIKE to have all of the readings as described above, but I can make due with the most important