Xavier wrote: To get the currencies from another website, the plugin hikashop_rates need to be edited. The url can be changed at this place.
Aaah, that's where it's from... ECB! Thanks Xavier!
Hmm, the ECB doesn't put out more in this format, it seems. So, I guess for more currencies to be included, the challenge is to find a different, equally reliable source, which uses (or lets you set) the EUR as basis and makes an XML in the same format available... sounds like searching the needle in the haystack, haha...