Underline Property [Excel 2003 VBA Language Reference]

XlUnderlineStyle

XlUnderlineStyle can be one of these XlUnderlineStyle constants.
xlUnderlineStyleNone
xlUnderlineStyleSingle

xlUnderlineStyleDouble

xlUnderlineStyleSingleAccounting

xlUnderlineStyleDoubleAccounting

expression.Underline

expression Required. An expression that returns one of the objects in the Applies To list.

Example

This example sets the font in the active cell on Sheet1 to single underline.

Worksheets("Sheet1").Activate
ActiveCell.Font.Underline = xlUnderlineStyleSingle

Applies to | Font Object