inserting a quotes via API

inserting a quotes via API

dear zoho team

i am triny to insert a quote record via api. But i can not post the exchange_rate 
i can create a quote but system gets exchange rate automaticly. we are trying to get lots of quotes from a different app so all of these quotes exchange rate is different from the system exchange rate. 

so is it possible to send exchange rate value with a quote or not?