Had the exact same problem. I was trying to work on a new method of inducing LDs recently and part of that managed to help with this problem. I spend a lot of time at my computer working, so I created a quick little program that randomly plays the first few seconds of a song. I usually set it to play every 15-25 mins and left it on while I worked and did an RC every time I heard the start of the song, even if I was really focused. I started to get a feeling for when the alarm was going to go off. When I made it go off exactly every 20 mins, I would get fairly accurate sensations a bit before the alarm went off, even after the alarm was disabled. Without playing the alarm at all, urges went away by the end of the next day.  

So I would just suggest setting an alarm that goes off as frequently as you would like. Instead of creating a program, the easiest way would be to get a free program like Audacity, and create a file that has the noise in the first few seconds, and whatever amount of silence you want after that. Then put it on your phone/computer and loop it in the background while you work. The important part would be to stop what you're doing immediately and do the RC, because if you delay the RC in your dream to finish what you're doing, you'll most likely forget by the time you're done.  

That's just my suggestion, but like I said earlier, it's just part of a method I was working on, so there's probably a better solution out there.