It seems to me that if you wanted to know the row # of a given
DataGridViewCell, you could just look at the RowIndex property of the
cell.  If you have the row itself then presumably you got it from
somewhere and could know the row # from that, but even if not you could
look at a cell in the rows cell collection and get a RowIndex from that.

But I'm not sure you need to do all of that.  If you want to format a
DataGridViewCell as the same as its current format but changing just
one thing, why not get the current DataGridViewCellStyle of the cell
(InheritedStyle or Style, as appropriate), create a new one using that,
and change whatever part of the style you want, leaving the other style
components the same?

Pete