Finding And Listing Duplicates

[Excellant]

I'm looking for some help in macro. I need to find duplicate from one column compared to another column then list them consecutively in another column. I have the rough macro working but need help making it more dynamic.

The user makes a selection of values in the first column manually. It then compares it to another column that I have to manually place the range numbers in the formula. I need the range to change in the formula each time a value is added to the compare to column. I tried with the letter z but the method error keeps coming up.

Also, the output column works but they don't list without having spaces between values.

I'm working at home & I don't have my notes and worksheets that I have at my work pc and my son asked me to do this for him this weekend.