>How can I determine the record that is in the top row of a grid? In other words the selected record is 10, but the grid has now scrolled down about 500 rows, now which record is now the 1st row? Isn't there a Y component compliment to the leftcolumn property?

If you're in grid (that's it has focus) you can use RelativeRow to determine your position in visible part. If grid doesn't have focus then you might achieve the same goal using GridHitTest.
Say current relativeRow = 5, then you're on 5th row in grid.
Cetin