Can I Use Project Funds to Go to Europe?

My paper about my funded research project was rejected by one of the two conference organizers in Europe I submitted papers to. They accepted a second paper on a different topic. I still need to hear from the organizers of the conference in Venezia but that paper is on the second topic too. So the question is whether I can use my research funds to go to Europe to present on a different topic. Of course I can talk to people there about the research project but it will be very much a general professional development thing. Snork Maiden had both her papers accepted, but she's going to the course in England during that time. I could present one of her papers but unless she registers we probably won't get a presentation slot.