Need Special Sort Method Completed

I have the following setup on a worksheet :

5427 Data
5427 Data
5427 Data
6565 Data
6565 Data
7765 Data

all I want to do is have the above table look like this :

5427 Data
6565 Data
7765 Data

The concept being that I can double click that row to see the additional information(i.e. expand to show extra information)

Real life use would be of such, the first column contains the invoice number, the 2nd 3rd etc contain item associated with such invoice.In grouping the column invoice number, you only have to look at one invoice, instead of it duplicating for each item contained within the invoice.

This will need to be done in an efficient manner(over 4000 rows need grouped)

I realize I could just create a list that has one copy of the duplicates, but I want to extract the original information as well. For example, it would look like the following :

Original :
1212 Data
1212 Data 2
1212 Data 3
2323 Data 1
2323 Data 2

Edited :
1212
2323

double click 1212 for :
1212
+Data 1
+Data 2
+Data 3
2323

Note : This grouping will also have to span across the whole row, sample rows :
Invoice# Price Color Weight Item
1212 Column1Data Column2Data Column3Data Column4Data etc.
1212 Column1Data Column2Data Column3Data Item2Column4Data etc.