Macro to compare items in a list with lists in miltiple other sheets based on criteria

Hi,

Please see attached an example of what I am trying to (unsuccessfully) achieve.

There are 4 worksheets:

R1 Items - this is a list of all items in a specific release (currently R1)
Tests - this is a list of tests
Bugs - this is a list of bugs
Changes - this is a list of changes

Tests, Bugs and Changes worksheets get updated via an external data connection. New items get created and assigned to releases and these come through each time the connections are refreshed.

What I would like is a macro that will list items at the end of the original list in the 'R1 Items' sheet (as in the example) of R1 items that appear in the other three sheets that do not appear in the 'R1 Items' sheet.

I'm currently spending a lot of time manually doing this comparison multiple times a day and would like an automated way to do it. Any help would really be appreciated.

Thanks in advance!