Shopify Internal Price Converter

[Vincinerate]

Hi all,

I want to set up an internal price conversion. Eg, I'm selling stuff in my Shopify store in local currency LAK. My items cost are in USD. Due to exchange rates changes, I don't want to update the selling price manually every now and then.
What I need is, I input my selling prices in USD, I set a customized exchange rate which will convert automatically ALL my pricings into LAK. Ie, $10, input exchange rate internally (18,000), the price shown on the store is ($10 x 18,000 = 180,000 LAK)