Yumdownloader and downloading a fully specified rpm package

Hello,

I have a machine with Red Hat Enterprise Linux Server release 5 (Tikanga).
This machine is subscribed to the Red Hat Network; I can run succesfully
"yum download rpmPackageName", or use the add/remove Software wizard.
However, I tried the following:
First , I installed yum-utils on this machine.

I downloaded yum-utils (the version was 1.0.4).
The reason for that was that by default yum-3.0.1-5 is
installed on rhel5 , and I followed and obeyed the following thread:
https://lists.dulug.duke.edu/pipermail/yum/2007-April/009748.html

Now after make and make install, I ran:
$> yumdownloader kernel-devel

It had downloaded kernel-devel-2.6.18-8.1.8.el5.x86_64.rpm.

However, I have a **different** version of the kernel on this machine:
"rpm -q  kernel" gives:
kernel-2.6.18-8.el5
and "uname -r" gives: 2.6.18-8.el5

I have two questions :
1) I want to download a specific rpm. In this case, I want to download
kernel-devel-2.6.18-8.el5.x86_64.rpm, which corresponds to the kernel
I am working with.
I know for sure that this rpm is on the installation disks, and I
assume it should be in some repository.
However, as you can see, "yumdownloader kernel-devel" downloaded
a newer version of the rpm, namely 2.6.18-8.1.8 instead of 2.6.18-8.

Trying to download a specific rpm fails; by specific I mean
giving the full, exact name of the rpm with the version; I tried:
"yumdownloader kernel-devel-2.6.18-8.el5.x86_64.rpm"
and I got:
Loading "installonlyn" plugin
Loading "rhnplugin" plugin
rhel-x86_64-server-5      100% |=========================| 1.4 kB    00:00
No Match for argument kernel-devel-2.6.18-8.el5.x86_64.rpm


Is there a way to download a specified rpm (when the version is differnet
when what you get when running "yumdonloader packageName") ?

I of course (needless to say) know of that simple workaround (to install
form a CD); but I am seeking for a real solution (for example, there are times
when you can only access that CD from various reasons).

2) Is there a way in such a case to tell yumdownloader to get a version which
corresponds to a certain installed rpm (like in this case, kernel-devel
should correspond to the installed kernel rpm).

Regards,
Ian