Hello, I need some expert advice please.

I have two workbooks, 'Orders' (open orders) and 'Trackers' (open/closed/cancelled orders). Orders contains an order number in col A and line number in col B. 'Trackers' contains the same in cols S and T.
The 'Tracker' also contains in col AE, comments relevent to the order. The total number of rows in each sheet is variable.

I would like to match the order and line numbers in both sheets and copy the comments from 'Trackers' into a new col in the 'Orders' sheet.
I've played around with functions and macros, but don't have sufficient knowledge to make any of them the work properly.

Thanks in advance for your help.