Custom attribute problem

Hi,
first of all, super plugin.
We use Booster and Woocommerce Plugin Price based on country, now I can’t set the feed up anymore. It works for the main currency, but not for the other one.
Main currency CHF, 2nd currency Euro.
I’ve tested all logical custom attributes for g:price :
Price (custom attribute)
Regular price (CA)
Regular currency prices (CA)
Europe Prie (CA)

There is another thread for this topic with no solution. How can I find out the custom attribute that works.
It just takes the normal currency price:
<g:availability>in stock</g:availability>
<g:google_product_category>886</g:google_product_category>
<g:gtin>978-3-03788-410-2</g:gtin>
<g:condition>New</g:condition>
<g:price>18.5</g:price>
<g:identifier_exists>yes</g:identifier_exists>

Have a nice day