installment payments and 'cells' in columns changing colour

hi,

need some help to impress my family

I have four columns.

B - base amt
C - paid / not paid
D - Amt paid
E - Date amt. paid (for D)

What I want to do is something like this
When I fill up any cell in column D , it will take the amt. and calculate how many rows below (sum) in column B are equal to it and will then put a 'paid' or 'check' mark in column C for the corresponding rows and also change the colour of the corresponding row in column B to 'green'.

attached is a sample of what i hope to achieve. any help/ideas would be appreciated.
thks