Ok, I have a spreadsheet that I"m creating to keep track of spending that is
coming out of two different accounts. I want to be able to keep a running
balance but in the same cell based on a condition. Is this possible. My
spreadsheet looks like this.

Cell A Cell B Cell C Cell D
1 9000 3000
2 R 100
3 P 50
4 R 400
5 P 100

What I'm trying to do is that based on if "Cell A" = "R", I want to subtract
"Cell C" by 100 and then "Cell C" becomes "8900". Then If "Cell A" = "P", I
want to subtract "Cell D" by "50" and then "Cell D" becomes "2950". So, then
when the next "R" comes up, I want to take the new total of "8900" and
subtract "400" from it leaving me with "8500" and continue down the line. Is
this possible? What's the best way to go at this?

The formula I have only works with multiple cells doing running balances and
I don't want that.

TL