Setting a home directory

When setting up a new score, it would be nice to set the directory that all saved files should be in. Sort of like setting up a project in Visual Studio or setting up a work directory in Matlab. Sometimes I do Save As and it will go to My Documents instead of the previously used directory and then I have to navigate in the Save window to get the file saved in the right place. Once I create a score, I only need to set the directory once for all of the files associated that that score (mscx, png, and then jpeg from the other applications).