How to recoed using Selenium RC?

WE have client-server application.In that we are invoking the applets (java) when click on the application.

We are using Selenium RC to automate the test cases.
After invoking base URL through Selenium, one login screen is opened.On that Login screen we are not able to record or not able to declare the diff. objects (eg. Username and Password fields)
(We are recording the steps through Selenium IDE )

So can u plz help me out.I have search a lot but coudnt get any solution.