Get instance of value in column

Hello,

I've an Excel file with the structure shown in below image (also in the attached Excel)

Basically this sheet is status report for testing samples.

There is Test Plan Number, Order of Test in the Test Plan, Sample Number and a unique identifier and some other columns with unique stuff. (I cannot use Remove Duplicates and I don't want to delete unique columns).

What I'm trying to do is without messing up the first few columns (no deleting), either with VBA or a formula that will just like in Column D that I wrote, will count the number of Samples from the row entries, then record that number in the 1st instance and delete the rest of the corresponding rows.

Obviously if it's an array function or something, it cannot delete, but VBA could. if Function I'd like the Column G to represent which instance of the test it is. I will then filter out if it's greater than 1. Again this 1st instance needs to work out how many total samples there is and record that in adjacent column.

Ow and each Plan can have same Order Number and Same Samples, hence why I'm using both 3 columns to differentiate the # of Samples. Data is not sorted, though it can be if it helps with the code..

Perhaps being Friday 5PM, I couldn't figure out where to start. I'm thinking of a slow way going through each cell with VBA and work out the details, but I feel there are better ways.

I just need some pointers. For sure it'd be great if someone could share a code , but looking for ideas for the moment.

Thanks!

ps. was there an Enhanced Interface - Full WYSIWYG Editing ? I feel like it'd help out with formatting....

Perhaps

=IF(COUNTIFS(A$1:A1,A2,B$1:B1,B2,C$1:C1,C2),"",COUNTIFS(Plan,A2,Order,B2,Sample,C2))

Copy & pastespecial > values, then delete the blanks?

damn! Glad I asked. As I said I was looking at complicated solutions or slow array formulas at the moment.
This works perfectly. Thank you Jason!