UnderlineType Enum

document.BeginUpdate()
document.AppendText("Normal" & vbLf & "Formatted" & vbLf & "Normal")
document.EndUpdate()
' The target range is the second paragraph 
Dim range As DocumentRange = document.Paragraphs(1).Range

' Create and customize an object  
' that sets character formatting for the selected range
Dim cp As CharacterProperties = document.BeginUpdateCharacters(range)
cp.FontName = "Comic Sans MS"
cp.FontSize = 18
cp.ForeColor = Color.Blue
cp.BackColor = Color.Snow
cp.Underline = UnderlineType.DoubleWave
cp.UnderlineColor = Color.Red

' Finalize modifications  
' with this method call 
document.EndUpdateCharacters(cp)

document.BeginUpdate();
document.AppendText("Normal\nFormatted\nNormal");
document.EndUpdate();
// The target range is the second paragraph 
DocumentRange range = document.Paragraphs[1].Range;

// Create and customize an object  
// that sets character formatting for the selected range
CharacterProperties cp = document.BeginUpdateCharacters(range);
cp.FontName = "Comic Sans MS";
cp.FontSize = 18;
cp.ForeColor = Color.Blue;
cp.BackColor = Color.Snow;
cp.Underline = UnderlineType.DoubleWave;
cp.UnderlineColor = Color.Red;

// Finalize modifications  
// with this method call 
document.EndUpdateCharacters(cp);