I have a company shares that I have bought shares on various...

I have a company shares that I have bought shares on various dates and averages. if I want to sell a particular parcel based on purchased date and average –

For Example

1/1/14 ABC Company 20000 shares at 9.30
5/3/15 ABC Company 5600 Shares at 7.00
15/07/17 ABC Company 3400 shares at 13.00

I want to sell part of the parcel I bought on 5/3/15
( Say want to sell individual contacts based on which one I want to sell )


how can I do that in Commsec. ?