One just needs to get the list of columns in the data table group and then change the names.
Names Default To Here( 1 );
dt = Current Data Table();
theGroup = dt << get column group( "Tests" );
For( i = 1, i <= N Items( theGroup ), i++,
theGroup[i] << set name( Char( i ) || ". " || char( theGroup[i] << get name ) )
);
Jim