looking for rhel4.1-xen kernel headers

[merlin at sztaki.hu]

Hello,

I've downloaded the RHEL 4.1 RPMs from the xensource.com website, and
installed the xen-kernel-2.6.16-xen3_86.1_rhel4.1 package.

I need the kernel headers for the xen kernel in order to build the IBM GPFS 
kernel modules, but I didn't find a "xen-kernel-devel" package. I've googled
a lot, but it didn't help.

Are the headers available from somewhere? If they aren't, how it is possible 
to build something with this kernel version?

Thanks for any tips/suggestions.

Regards,
Misi