checked Property
Sets or returns a Boolean that represents whether a check box or option button is selected.
expression.checked
*expression * Required. An expression that returns one of the objects in the Applies To list.
Example
The following example inserts a checked check box into the active document.
Sub SelectedCheckBox()
Dim objBox As IHTMLInputButtonElement
ActiveDocument.body.innerHTML = "<input type=""checkbox"" " & _
"id=""newbox""> This is a selected check box"
Set objBox = ActiveDocument.body.all.tags("input").Item("newbox")
objBox.Checked = True
End Sub