I've got this bit of code so far:
=IFERROR(INDEX([EbayAmazonWeeklyReport.xlsx]Sheet1!$A$2:$F$2359,MATCH(C2,[EbayAmazonWeeklyReport.xlsx]Sheet1!$C$2:$C$2359,0),2),"")
This matches up the number in column C2 on one spreadsheet, with column C2 on another spreadsheet. Then brings over the info...