Dataformat in Datagrid

How do I use the property Dataformat in a datagrid?

I tried...

datagrid1.columns(0).dataformat = "dddd, mmmm dd, yyyy"

...doesn't work or

set datagrid1.columns(0).dataformat = "dddd, mmmm dd, yyyy"

...doesn't work either

Thanks

Are you tried with the Format() function? or In the DataGrid Properties in the Colums Tab