Given a number (say... 30)
I want to make a row in an excel sheet that would decrement a value defined by a certain cell (say... 0.1) and a stop value defined by another cell(say... 0)

say A1 = Step Size = 0.1 and A2 = Stop Value = 0
B1 = Start Value = 30

How do I do something like this?
-- Using Excel 2003

Thanks...