Songs on iCloud but not mapped in iTunes to local version

Hi,

I have all my music in two places:

1. Backed-up onto an external hard-drive

2. On iCloud with iTunes Match

Having all my music on iCloud serves a purpose for my recent Apple product (iPhone; Mac; iPad), however I have an old iPod which I hook up to my car (5th Gen, I believe.)

The issue I have is that now when I want to update the music on the iPod, it only lists the files I have stored actually on the computer - which is nothing becase it's all on an external drive.

Investigating a little further, I notice that all the songs in my library have a location of 'iCloud' as opposed to my Ext HDD. I have tried moving the iTunes Library (*.itl) to the Ext HDD and opening iTunes holding the Option key ('Choose Library...'), however this hasn't worked.

What I am looking for is the following:

1. All my music on my Ext HDD, both as a back-up and to support my legacy iPod;

2. All my music on the iCloud using iTunes Match;

3. When I plug-in my Ext HDD, iTunes 'points' all the songs to the local version of the file as opposed to iCloud.

Any help much appreciated.