"redhat-config-packages --isodir=/opt/linux/Fedora/rpms" does not work
 

I have installed Redhat from Bootable CD. when i add more packages in add/remove, its path is from CD-Rom. i want to copy the sources into Hard Disk and change the path from CD ROM to Hard Disk. How can i do?
i tried "redhat-config-packages --isodir=/opt/linux/Fedora/rpms"
did not work..
gives various errors..i've a copy of all rpms deployed with fedora the .discinfo and the treetab file is also updated..nothing works. please help.