How can the Bahrain Dinar currency be set up to support 3 decimal places?

With Bahrain now introducing a 5% VAT our advisors are saying

"We note the figures reported in the VAT return and supporting schedules are rounded to two decimal places. As Bahraini Dinar is a three decimal currency, we recommend you review/configure your system to ensure it captures the tax base amount (i.e. amount excluding VAT), VAT amount and amount including VAT rounded to three decimal places for all the transactions"

How do we overcome this?