Pull information from multiple sheets

Hi folks,

An expert helped me out with this script (thread ref: "vba script for % price change over the period"). This is pulling out the relevant information from one sheet "Transactions" against the unique transactions. Please refer in the sample data attached.

I wish to add one more sheet "PO" and pull out total quantity ordered in the "Output" sheet against the unique transactions. This should come from the "Qty" column in the "PO" sheet. Hope I am clear. I am a newbie and struggling to modify the code accordingly. Please support. Thanks in advance.