Thanks for the quick reply.
It seems that the zip file(filled with PDFs) contains many helpful tips. However, I do not see any pertaining to OE. Only: AJ, AP, BR, GL, IC, IN, SQ, SR.
The CSV files I have may be the wrong ones (oeorder2.csv, oeorder3.csv,...). They don't seem to be of much help.
Is it possible to add multiple items to an imported order in OE?