I would suggest not trying to build any inteligence into the file names. Use the same, dumb, unique number with no letters or spaces for both the part and the drawing (providing this is possible with your MRP system). Different file types can be distinguished by their file extensions and searching can be done with the "search solid edge files" function, using the file properties rather than the file name. Anything else becomes too much of a nightmare to control and allows duplication of parts through misspelling the name or adding a space or something. I have seen this happen in a couple of places, and the duplicate parts multiply quickly until it becomes impossible to determine which is the correct one.
The downside to this is that it requires a bit of discipline in filling in the properties in a consistent manner, but this can be done easily with the help of a simple VB bolt on. Also, use a really simple folder structure - it will pay dividends later on.
You could try Insight - which works on a similar principle, it is supposed to help the workflow and facilitate easy quick & searching on properties but I have very limited experience of using it so I can't say if it really helps or not.
