I wouldn't worry too much about it, you can add some cals to your next meal, but I wouldn't go overboard. If you miss a meal, you miss a meal, it is what it is.
I think the bigger issue would be to adjust your eating schedule around work so that your not missing meals. I know it can be difficult, but if you fail to plan, you should plan on failing ... or some kinda nonesense like that lol.
There are a lot of eating plans that work around large gaps in eating time, this may or many not work well for you, but I've been reading up on Intermitant Fasting lately, and its pretty interesting.
http://www.leangains.com/2010/04/leangains-guide.html