In reply to Mr Fuller:
Hmmm... I can't see an obvious method. Which seems a bit of a drop-off.
I also see 'Ordenance Survey', and no mapping source attribution or licence #...
If you do a right-click 'save page as', the resulting hmtl file contains a set of CSV lat/long coordinate quintuplets (search for 'kml'). I'm not sure what the three values after the lat/long values are; maybe segment length, height, and ???. In the example I saved, the last two figures were zero.
I'd take those values and create a GPX file from them (as I've written plenty of AWK scripts to muck about with GPX files). Point me to the route in question and I'll see what I can do.
[edit: done: found a handy CSV to GPX script that only needed a bit of tweaking]
Post edited at 13:42