Go to
http://mirrors.kernel.org/mandrake/M...inux/official/ and select your version, then follow to your arch, and /media/main/release/
Most probably it will be i586 or x86_64. (latter for 64 bit support. If in doubt chose the first one.)
there you will find your rp-pppoe version. You might also need one or more of the following dependencies:
* ppp
* rpmlib(PayloadFilesHavePrefix)
* rpmlib(CompressedFileNames)
* bash
* libc.so.6
* libc.so.6(GLIBC_2.0)
* libc.so.6(GLIBC_2.1)
* libc.so.6(GLIBC_2.3)
* libc.so.6(GLIBC_2.3.4)
* libc.so.6(GLIBC_2.4)
* rtld(GNU_HASH)
* rpmlib(PayloadIsLzma)