hello all

I have a problem that is not so difficult but I am not a programmer and VB
starter.
I need to calculate percentage from some values but ofcourse it must be
automaticaly.
I have one column (A...there are more rows but I only pasted 4) in which I
will write numbers manually. In column B, there will be percentage (e.g.
20%) that is the same for the whole B column (but for the other documents it
must be changeable). when I manually write number in A column I wont that
automatically in column C percentage of column A is written in B column. at
the same time the complete sum of A and C column must be written in the
lowest row below. ofcours as I am entering the values.

I have no expiriance in excel except reading excel documents. I supose that
this is done through macros and visual basic.
I supose that it is simple problem for some expirianced but for me it will
take days and days to solve it.
If someone has time to work around with this I would be grateful.

ps. sry for my english, it is not my native language.

A B C
37085
37110
37114
37118

sum: