how to import xml files into marketpress

I got the following xml file (attached as pdf) from an external online shop and I would like to import it having the "button to buy" and the image linked to the external shop.
I tried "wp all import" but without success. Moreover to import the image it is necessary to buy the premium version but not sure if it will work.
I tried also wordpress importer but I get the message that the file is not a wordpress compatible file.
Maybe there are other plugins to do it?
Thanks for your help.