Help with Saved Values

[JarethD]

Okay, so heres the dealio. I'm trying to create a "complicated" kind of processing that should be automated instead of me changing the values constantly manually. How I go about doing that, I have no clue.
Here is what the table roughly is looking like:

A3: Stat, B3: Growth Points Earned, C3: Exp Gained, D3: Growth Rate, E3: Weapon Change, F3: Item Change, G3: Enemy Change, H3: Current Growth Points, I3: Starting Growth Points

This continues for 8 lines, with a secondary Calculator later on at:

A13: Exp Calc, B13: New Exp Value, C13: Old Exp Value, D13: Exp Earned

How the table currently works: Input value into New Exp Value, It then subtracts the old Exp, giving a value under Exp Earned. Exp Earned is translated into Exp gained for the 8 lines in the first coding, which then causes a value to become created for Growth Points Earned. Growth Points earned is calculated via: =C4*(D4+E4+F4+G4) [Exp Earned * (Growth Rate+Weapon Change+Item Change+Enemy Change).

What needs to be done: Make the table automatically add B4 as in the example, to I4 to create a value for H4, and for it to stop after doing the calculation once, as to not cause an infinite string of numbers going on and on. Not only for the first row(Row 4) but for all 8 rows(Row 4-Row 11). Having to plug in the growth points earned each time is tedious and time consuming that I would rather skip out on to actually make progress within what the spreadsheet is trying to accomplish!

Hope someone has an answer because I've wracked my head on this problem for a while and can't figure it out.