Either we know where the money is going to be used, and then we can participate in the event, or we can take charge of handling the finances so it can be given to the project or country for whom it is designated.
However, there are certain cases where it doesn’t matter where the money goes, where our job is to liberate sentient beings from the lower realms and even from lower nirvana by spreading the Dharma. In those cases it’s OK, even if we don’t see where the money is going. The other groups can organize the event and we are given the opportunity to spread the Dharma.