I have the following issue, I will make a simplefied explenation here.

I have the Following Data

A B C
1 1
2 V
3 V
4 1
5 1
6
7 V
8 1
9 V
10 1 5

I have to count the total of a predefined, but dynamic range.

The Value of C10 should be the sum of B9:B5 (so 5 rows up). But if for
example the value of A9 is a V, the sum is going to be B9:B4, because
if there is a V in a row, there will be no value in the neighbouring
cell. So you see this is a dynamic calculation and needs a variabel

The Value in column A is ALWAYS V or nothing., The value in Column B is
is always 1 or nothing. The Value in Column C is the Sum.

(This in fact is a part of a calender where I need to calculate the
number of nights people worked in the field. It has to calculate the
number of nights in the field for the last 30 days but If it was a
National Holiday or I toke a day off, the number of absences have to be
added to the 30 days. This was no problem when I had a holiday for 5
days in those 30 days (it should count up to 35 cells) but when someone
has also a holiday on day 32 and 33 I needed to count 37 days etc.....
So in total it will be used in a 335 rows)

I want to do this via a macro in VBA because I want to use and
transform this function for use in other documents as well.

Can someone point me in the good direction? I haven't got much VBA
experience but I need some help.

greets