Old Excel spreadsheet for measuring pressure and temperature - how to modify conditions

I have an old 32 bit excel spreadsheet that I got from Omega engineering which has zero support. The problem is I don't know how to set the initial conditions such as units = psi and relabel a column that is mislabeled to humidity to "absolute pressure". I use the system to measure a critical air pressure for our labs and it is a PITA to set these initial conditions every time I start a new week of data collection.