Use the Font property to change the font for items or columns that match the criteria. Use the Font property only, if you need to change to a different font. 

You can change directly the font attributes, like follows:

• Bold property. Bolds the cell or items
• Italic property. Indicates whether the cells or items should appear in italic.
• StrikeOut property. Indicates whether the cells or items should appear in strikeout.
• Underline property. Underlines the cells or items

The following VB sample changes the font for ALL cells in the first column:

With Group1.ConditionalFormats.Add("1")
    .ApplyTo = 0
    Set .Font = New StdFont
    With .Font
        .Name = "Comic Sans MS"
    End With
End With