An alternative would be compiling needed libraries from source.
If the version number of the library is the same, I don't think it would be a problem using an RPM from a newer distribution. A more recent distribution will probably have different library versions however.
If they are backwards compatible, this may not be a problem.
Red Hat 7.2 is very old. You might want to consider upgrading to a newer version of Red Hat, or installing Fedora Core. Perhaps the only thing that might stop you would be if you are dependent on binary kernel drivers. But even there, installing a newer distribution and installing the same kernel version may be possible.
Another website for finding RPMs is www.pbone.com.
You can filter the responces to Red Hat 7.x.
However there may not be any.
Another thing to consider is using the 'mc' Midnight Commander program. It runs in the console, and allows you to browse the files in an RPM as it they were in a filesystem. So you could manually copy the library file you needed and run 'ldconfig' yourself.