datagrid 2 problems(header and mappingType)

[Gil]

Hello
my name is Gil and I'm a new developer in vb.net
I Have 2 questions:

1. after hiding a datagrid column like this:

gDs.Tables(0).Columns(0).ColumnMapping = MappingType.Hidden
I don't know how to show it again(cancle the hidding)

2. I can't set the datagrid header text to show multiline text
i wont to show to lines like this:
line1: customer
line2: name

and i used vbcr, vbCrLf,Environment.NewLine, /n/r, nothing work...

thanks, Gil