I am trying to develop a template for researchers to use to help them develop
project budgets.  I am having a problem with one particular formula and am
not clear if I need to use "lookup", "match" or "if", or some combination of
the the three, or something completely different.  Here is the problem:

Employees are given raises one time a year (either in July [Faculty change
date] or October [staff change date]) depending on your status.

A grant budget can start in any month of the year and will generally run for
a one-year period.

example:  A grant starts in July and ends in June
Staff current salary is 20,000
Staff increase is in October at 5%

Therefore,
Salary in July, August and September is 20,000
Salary starting in October is $21,000
Total salary paid for 12 month period = 20,750 or ($20,000/12*3) +
($21,000/12*9)

I thought about using a nested "If" statement like below.

If(GrantMonth=January and status=Faculty,CurrSal/12*6,
if(GrantMonth=February and status=Faculty,CurrSal/12*5, etc.)

I understand that only 7 if statements can be nested.  How can I achieve my
result using a formula?

I don't understand how to use the lookup command.