Tracking various colors of money

Okay, I am going to try to describe my problem as best I can. So I have money coming in from different organizations, and each check that they cut carries a 'code' of sorts that restricts what I am allowed to spend the money on, although some money is so coded that I can use it for everything. They provide money based on a budget for broad-scope tasks that need to be completed by my organization, and, once each task is 'fully-funded' per the budget, the money for that task dries up. However, the money comes in irregularly, and oftentimes I have to pull some money from an account that is assigned for one project and use it on another, because the more urgent project is not funded enough to meet its obligations. To use a metaphor, I have a bunch of pots on one side that may or may not mix with each other, and a bunch more on the other than I have to fill. In order to keep myself from, for example, winding up with nothing left but money that is not coded for the remaining projects (which would create a frustrating admin drill for everyone involved), I want to get ahead of this and develop some kind of tool that can help me track what's in each of the pots on both sides. Unfortunately, I am not enough of a spreadsheet wizard to create anything more useful than an itemized list of what money I've received and what I've sent out, which can grow quite out of hand. Does anyone have any experience with this sort of problem? Or know of a tool that they could share?