Congrats for making it through Attack, northerngirl!
Yes, work can be tough as there don't seem to be many Dukan-friendly snacks you can stock in your desk drawer (especially on P days). And most allowable foods need to be refrigerated. As others have said, the secret is planning and being organised. I keep a few tins of diet coke, sugar-free sweets, gum, some cocoa powder and a few packs of UHT skim milk at the office. Preparing food from home is great but if you make a PV meal the night before, you can't eat the veg the next day. So I often make protein meals in the morning: tuna salad (with yoghurt or cheese, herbs and some onion), chicken salad, crab sticks, boiled eggs, ham and cheese slices... And then slowly scout around the eateries in your area to see what is available. I live in Shanghai so I fall back on sushi a lot, but it's not cheap. Chicken caesar salad without dressing on PV days.
But you'll probably find that you don't get very hungry during the day with Dukan - I've really been surprised by the lack of cravings.
Good luck, and be patient with the results. Sometimes you'll go for a few days with minimal loss, but then all of a sudden the scale starts to move quickly.