Oh, I used that website a lot a while back but they change it.  I have my
own custom data grid so in concept it's extended but I never did anything to
the row header.  Most of my changes have been to the data gird itself in
regards to displaying data.

I think you would have to handle panting the grid yourself to add text which
would be rather a pain.

My suggestion would be to hide the row header and create a custom grid
column that looked like the row header.  You could then select the column on
click if you want.  Sort of depends how many of the standard features of the
row header you need.

You might also be able to replace the icon on the row header but you are
very limited on size that way.

Regards,
John