Is it possible to populate exchange rate using client extension

Hello everyone,

I will appreciate if someone provide some pointers. I wanted to know before diving into it, we wanted to implement internet expenses so that a user can pick exchange rate type for each expense line rather than entering manually based on setup.

Using DFF at the expense report line level we can give exchange rate type to pick. after this here, Is it possible to validate and populate GL conversion rates into "Exchange Rate" based on exchange rate type entered by user.

Thanks in advance to all..