My sister lives in Morecambe - small world.
If you have Excel 365 and are looking for a seperate list to count the duplicates then i would recomend converting the range to a table and using something like the below formula:
=SORT(LET(r,Table1[Column1],u,UNIQUE(r),HSTACK(u,COUNTIF(r,u))),2,-1)
Or maybe filtered to only numbers with counts > 1:
=SORT(LET(r,Table1[Column1],u,UNIQUE(r),d,HSTACK(u,COUNTIF(r,u)),FILTER(d,INDEX(d,,2)>1)),2,-1)
If you want conditional formatting to highlight the duplicates then:
Select the column in the table you want to add the CF to
Under the 'Home' tab in the ribbon select 'Conditional Formatting'
Hover over 'Highlight Cell Rules'
Select 'Duplicate Values'
I recommend putting any data you have for this in a table and not just a range, the reason for this is that the both of the formulae above and the CF will grow with the data as you add it so there would be no need to worry about referencing the end of the range within the formula.
And yes as pointed out above, it is always good to set a meaningful title to a thread, this one could have been somthing like "Counting Duplicates in a range" or something.