You can see the plugin setting in the image. Insert the definition of language / currency relations into Lang/Currency relations field. Language is defined by code (i.e. en-GB). You can find this codes in the Language Manager. Currency is defined by a 3-letter code like EUR, USD or CZK. You can find these in VirtueMart > Currencies Manager. Relations between language and currency is made by simple syntax language1 > currency1, language2 > currency2,...
Example: cs-CZ > CZK, en-GB > EUR