Right now it looks like this is as close as I can come: http://www.bbc.co.uk/radio4extra/programmes/schedules.xml
Because the play it again links are only good for seven days, this details of this example will soon be stale, but it is better than nothing.
On the web site: http://beebotron.org/public3/radio4extra.html, there is a link to the program "Jenny Stephens' Project Archangel, Episode 4 - The reason for Mike's involvement with the Nablovski colony is revealed. (4/4) [6 days 14 hours]" which is "http://www.bbc.co.uk/mediaselector/4/asx/b00wmzn1/iplayer_intl_stream_wma_lo_concrete"
On the web site: http://www.bbc.co.uk/radio4extra/programmes/schedules.xml" there is a reference to the show, but the pid is listed as b00wmznd. Tantalizingly close, but...
More research has revealed some more information. The link http://www.bbc.co.uk/programmes/b00wmznd.xml has an entry that displays the value b00wmzn1 in the tag
I think that this is what I need to be able to design an application that will use the data from the BBC XML files to build a command line string to record a show.
Now, how do I program an application in Squeak?