Input a list of numerical values from a Excel column

I am pretty much a noobie, so go easy on me.

I am trying to create a small program to do a mathematical average of values from a random column in Excel. Thus the copy/paste action.
The number of values in this column varies.
I want to be able to paste the values into a text box or list box, then be able to do some calculations with these values, then display the calculations on a label or something.

i am able to do it with input boxes and a set number of values, but that does defeat the purpose.

Any help is very much appreciated.