Afternoon group... you are all well I trust?

I have been writing VB stuff for years b ut only now has the
requiremement fallen upon me to het involved with macros in excel and
whereas the actual code of the macro is fine, I am having dificulties
getting my head round the concepts.

I have a specific problem that i would welcome comment or advice on:

I have a worksheet that may or may not have a value entered ina
specific cell. When a value is entered I need to grab that, do some
work on it and update some cells on the same row.

How on earth do I grab the reference for the cell that just changeds
and how do i pick from that the row in order to address the cells
further along.

This sounds pretty basic but I have been scratching my head for two
days now and can't seem to find a solution when googling - most likely
I just can't get the wording right - I get loads of stuff but none of
it really suits what i'm after.... HELP!!!

all the best

H