Upload Products from CSV to play.com product upload spreadsheet

General information for the business: We Sell over 50,000 SKU's of clothing across Amazon, eBay, Amazon and our own website
Industry: Internet/Software
Description of excel work: Take a CSV file of our products which includes SKU, title, description, brand, image filepath, size and colour and convert that data into the play.com marketplace upload spreadsheet.

Automation is required as some of our colours and sizes are not in play.com's database (only item colours already in the play.com databse can be used) so Vlookups and macros may be required to convert our colours into sizes acceptable to play.com.

Also each product requires a play.com category attaching to it from a selection of play.com categories.

We have approx 40-50,000 SKU's to be worked on.
Extra notes:

Colours are a bit of a problem. For example we have colours such as Forest Green and Kelly Green in the same product. Play.com only has the colour "green" in its database and you cannot use the same colour twice in the same product.