OK, I tried John's method in Photoshop CS2 and found it didn't behave as I would have liked it to. I may persevere with using the channel mixer method in the future.
I did find that Capture 1 v3.7.7 can use a series of B&W 'profiles'. I've imported these profiles (taken from an evaluation copy of C1 v3.7.7 Pro) into the copy of C1 v4 beta2 that I'm currently using. By using the B&W Yellow Filter emulation, and then tweaking the contrast/saturation to suit, I've got fairly close to the look and feel I was after. If there's any C1 users out there who've used the jfi labs B&W film emulation filters (found here
http://www.jfilabs.com/), I'd be interested to know if they are any good.
If anyone is interested, the photo is a section of the Normandy coast near Port-en-Bessain looking towards "Gold Beach". The remnants of the Mullbery harbour at Arromanches can be seen on the horizon.
Duncan