Lee,

If you want to import order lines in PO, you have to add "order_line/product_id/id" field to your sheet and give product ids in this column. For example order1 has 3 order lines. in id column add unique id to that order and add these 3 product ids in "order_line/product_id/id" in adjescent rows. i.e you have to use 3 rows for one order, in first row under "id" column give id of order and in "order_line/product_id/id" column first product id, Give next product id in next row of column "order_line/product_id/id". Like this you can add any number of order lines to one order. If you want to add another order add unique order id in "id" column and proceed the above process to add order lines. I hope this will help you Lee. Good luck.

To order line from csv, You can check HERE

Hope it Helps to you

On test DB, create a purchase order, export to csv, open it with spreadsheet.

To test, edit data and import the csv file

Example csv file, it works on my server:

Order Date,Supplier Reference,Supplier,location_id/id,pricelist_id/id,Order Lines / Product,Order Lines / Description,Order Lines / Quantity,Order Lines / Unit Price,Order Lines / Taxes,Order Lines / Scheduled Date
2014-1-11,Supplier_Reference1,Valid_Supplier-1,stock.stock_location_stock,purchase.list0,,,,,,
,,,,,Valid_Item-1,Valid_Item-1,500.00,3.50,Valid_Tax,2014-1-11
,,,,,Valid_Item-2,Valid_Item-2,1000.00,3.50,Valid_Tax,2014-1-11
2014-1-20,Supplier_Reference2,Valid_Supplier-1,stock.stock_location_stock,purchase.list0,,,,,,
,,,,,Valid_Item-3,Valid_Item-3,350.00,3.50,Valid_Tax,2014-1-20