Need to disable currency converter on all pages, except Checkout, Single Product

Hi!

How can we disable the converter on all pages, except Single Product, Checkout and Cart page?

Our store is in Romania, we use RON currency.

All Products are set in Euro in backend, because we buy all the products from distribuitors from Europe.

We need to display the price in euro in Homepage, Shop. And on single product to be EURO and under it, conversion to RON.

Thanks a lot!