I think, You should be talking about a subfile, which will have a <b>position to</b>, where you will need to enter the starting character(R*).
You can use the SETLL indicator to point the File to the required position. In this case, to point to the records, which will start with ‘R’. From there, you can use your normal Read Operations for displaying the records which will start with ‘R’.
If you didnt mean this exactly, Post back here, with your requirement.