The reference to the current sheet should be simple enough. You create a field using the system parameter CTAB, and then name your tabs the same as your sheets. Perhaps this only works with multiple tabs instead of separate sheets, but then again I have a field that states my drawing's file name, so if the sheet file name is.....then you see where I am going with this?
If by some odd chance my nattering was useful -- that's great, glad to help. But if it actually solved your issue, then please mark my solution as accepted