Exchange rates

Hi Friends

I have a scenarion of 7 company codes with each having different currency. Because of this reason, exchange rates are to be entered into system for different combination of currencies on a day to day basis. If I want to maintain it manually, it will be a tedious job. Is there any way to get this rates into SAP system automatically ? What configuration I have to take up for automatically connecting the SAP system to any other site providing exchange rates automatically ?