Macro to separate 2 identical rows by adding value to 2nd cell

[sncb]

I need to separate two identical rows using VB code by adding a 2 to the end of the first cell on the 2nd duplicate row: eg in A3 from GB to GB2 so as to separate the 2 rows and have a unique identifier to separate the two identical lines.

Thanks in advance to assist.

Excel Workbook
	A	B	C	D	E	F
1	PO Type	PO Number	Type/Number	Order date	Keep	Salesperson
2	GB	1500	GB1500	23-Feb	N	Michela
3	GB	1500	GB1500	23-Feb	N	Michela
Sheet1