Hello Zoho Team

In order to comply with local tax regulation we do need to display total amount of invoice in double currency for every invoice ( USD as base currency , KHR as local currency with a fixed monthly exchange rate defined by local tax authority) in invoice custom template . It seems that we have several option but none of them are really convienient: 

- Select foreign currency at customer level --> Item are at 0 selling price by default when creating the invoice as we need to create a price list in KHR . But each selling price need to be updated manually and not updated automatically according to exchange rate configured. Furthermore our customers will pay anyway in USD so confusing for A/R. 

- Add a custom field in invoice with Total amount in KHR , but there is not formula available in Custom Field / Zoho Books / No way to retrieve the exchange rate as a variable defined in the multi-currency settings

- Add a script to calculate customer Field (total amount in KHR), but we cannot retrieve the name of variable exchange rate KHR and wondering it it will be  available in invoice issued from  Subscription Module . 

Thanks for your help