I am amazed by everyone's determination to go for the complicated solution. The 737 (at least) has a perfectly good map holder. Anyone who has an ipad will have tried mounting it in that obvious place and discovered the clamp will not hold it. If the company provides everyone with a dollar piece of plastic the right length then your problem may well be solved.
It certainly holds more reliably than suction cups etc. One end wedges solidly against the window frame and the other in the clamp. This is the kind of thinking that has got most of our employers in serious financial difficulty. At least add it to your list of things to trial before you rubbish the idea.