Calculate column based on previous value of itself in previous row

[rtrigor]

Hello, I have this initial table:

TableA:

Row	ValueA	PCT
1	100.000	0
2	100.000	8%
3	100.000	5%
4	100.000	7%
5	100.000	6%
6	100.000	3%
7	100.000	5%

And I need to perform the following calculation for ValueB from ValueC:

Row	ValueA	PCT	ValueB: WHEN Row=1, ValueA WHEN Row>1, (Pevious(ValueB) - Previous(ValueC))	ValueC = ValueB x PCT
1	100.000	0	100.000	-
2	100.000	8%	100.000	8.000,00
3	100.000	5%	92.000	4.600,00
4	100.000	7%	87.400	6.118,00
5	100.000	6%	81.282	4.876,92
6	100.000	3%	76.405	2.292,15
7	100.000	5%	74.113	3.705,65

Any clues?

I couldn't find a formula that worked using Previous() neither Peek().