Increment number by itself formula?

I am looking for a way to make a number equal itself plus another number a set amount of times.
In programming language, you assign value to X and Y then set a parameter (Z) for the amount of times to run a X=X+Y loop and you are done, but I am lost on how to create this formula in Excel.
Cell A1= Number of Times X will be added to itself or Z
Cell B1= The Starting amount for X
Cell C1= Y: The amount added to X every loop
Cell D1 = Total
Can this be done?
Excel version is 2003.

Thank you for any help that can be provided.
-Zumsing from NE

In D1: =B1 + A1 * C1