This is currently a drawback of Zoho. It operates in one currency only but you are able to specify that currency. Options:
As a Zoho Alliance Partner we are able to suggest and push feature requests, we would be happy to suggest this one for you.
You could make the base currency USD. Then add custom fields for each other currency in the opportunity. Establish base exchange rates and then if you are pain in Francs you could add the Francs value in the Francs field and calculate the corresponding amount in USD for the sale amount. You could then create reports for the other currencies.
As a Zoho Alliance Partner we are able to suggest and push feature requests, we would be happy to suggest this one for you.
You could make the base currency USD. Then add custom fields for each other currency in the opportunity. Establish base exchange rates and then if you are pain in Francs you could add the Francs value in the Francs field and calculate the corresponding amount in USD for the sale amount. You could then create reports for the other currencies.