Just drag a CSV file that you would use to upload items onto the Browse button below (or click it of course) and hit "Get modified CSV".
What this does is uploads all the image references found in the 7th column (anything starting with http://site.myheritagewear.com in the 7th column) to eBay's image hosting on your behalf, and replaces the values in the CSV with the new 'picURL'. It also assumes column 9 is Relationship and 10 is RelationshipDetails. If that must change let me know.
I've only tested it with 4 images at a time and it's pretty quick, but I recommend only doing like 1000 at a time because there is apparently a 5000 daily limit and I don't know for sure how much the server would freak out with reading and transferring all this data around in a few milliseconds :) So in other words, if it dies at 1000, try 500, but if it breezes through 1000, try 2000 etc.