Given that you have just ten hours, Rasher is probably about right.
If you really want to lob in some roads other than motorways, it's easy to drag a Google maps line about.
Here's an example:
http://maps.google.co.uk/maps?saddr...2S9Gw&gl=uk&doflg=ptm&mra=luc&via=1,2&t=m&z=8
It follows the well trodden Calais to Cambrai, via motorway. Then goes on a direct diagonal South-East (the only way to go, given your constraints) down the faster non-motorway roads, thro' Sedan and the delights of Luxembourg, before picking up the motorway again towards Strasbourg. From Strasbourg you have to cross the Rhine (you have no choice) so just pick-up the direct main roads again.
That is a shorter distance than the motorway all the way option but will, not surprisingly, be slower and will take longer. It's doable in 10 hours, even allowing for stops but it won't necessarily be 'easy' per-se.
My hot tip.... If you have one, load your chosen route into your GPS. Keep an eye on two items:
(1) Distance IN MILES (it's odd how some bods get in a panic over km's) remaining to destination
(2) Estimated ARRIVAL TIME at destination (don't forget to re-set the GPS device to reflect CET time... or you'll need to add an hour, some bods forget that in the excitement of a holiday)
Watch (1) and (2) as you go along and be prepared to change your route to suit. That is where a half decent paper map really will be your best mate, trust me.
I did exactly that just yesterday, returning from Dijon to Calais, planning on going via Peronne. It's a route I know well. As we went along it became plain that we would end up chasing our tails if we dawdled in Peronne, so I switched my plans at a convenient stop near Soissons. Ten minutes with a map, a pencil and paper saw us taking an alternative route to cut a corner..... and we had a decent 45 minute lunch stop out of it into the bargain... still making it to the Chunnel in good time, despite the access road off the motorway being shut.
In short, be flexible. Plan something that suits you, not me, Rasher or anyone else. Then be prepared to change depending on how your day unfolds. To make changes, you will probbaly need a map, not least as you'll not have your PC with you.
As Google maps shows, there really is only one or two reasonably direct options available to you if you want to complete the schlep in 10 hours over one day. Play it safe and motorway as Rasher suggests (certainly nothing wrong, as your real aim is to get to Pension Williams in 10 hours, let's not forget) ... or try a bit of a hybrid.... Only on the day will you know how you get on.
