I'm using a Dell Dimension 4550 to run various Linux OSes, mostly from the 80GB internal HDD.
However, I want more but the internal drive is full!!
But, being a Dell computer, there is no option available to boot from an external (usb) HDD so I have being using this guide which explains how to modify the initrd file and subsequently reconfigure the kernel module to allow booting from a usb HDD even when the computer BIOS does not recognise the drive.
The guide is written for Ubuntu and it works great for this OS as well as for Ubuntustudio. I have also managed to use it to boot to SimplyMEPIS on a usb drive.
However, I'm currently having problems adapting this method to boot PCLinuxOS from an external drive.
There appear to be two reasons for this:

1) the files to be modified to allow booting from the usb drive are not available in PCLinuxOS. These are
/etc/mkinitramfs/modules (or /etc/initramfs-tools/modules in newer Ubuntu) and /etc/mkinitramfs/initramfs.conf (or /etc/initramfs-tools/initramfs.conf in newer Ubuntu).
I would like to know what are the equivalent files in PCLinuxOS.

2) Having made the required modifications, the next step is to rebuild the initrd files. This is done using
dpkg-reconfigure linux-image-<kernelversion>
However, PCLinux doesn't seem to use the dpkg-reconfigure command as it's not contained in /usr/sbin/ and typing this in a terminal/konsole in PCLinuxOS gives a "command not found" error.
Once again, my question is, what is the equivalent command in PCLinuxOS for this procedure?

What is strange is that I was able to get PCLinuxOS to boot from a usb HDD on this same computer about a year ago. But, for the life of me, I just can't figure out what I did. In any event, it does show that what I'm trying to do is absolutely possible if only I wasn't so forgettful.

I'll be grateful for any advice.