Copying data from one file to another

Hello,


My programming skills are a little weak so i require some help with the following:
I am trying to write a macro in excel 2010 to look up info from one file and then copy it to another. The problem i am having is that i need the macro to compare a column with a PO (purchase order) and then a column with an item number from one file and match it with a PO from one column and a item number from another column in another file. If those match I want it to copy a date from another column "ETA" into the ETA column in another spreadsheet. If the ETA column is blank, then i want it to disregard and move on.

Is there anyway you could help me?

Tony