Use the following
Code:
On Error Resume Next
If CheckBox1.Value = True Then
Set RngSrc = DocSrc.Bookmarks("A").Range
Set RngTgt = DocTgt.Bookmarks("A").Range
RngTgt.FormattedText = RngSrc.FormattedText
RngTgt.Bookmarks.Add "A"
Else
Set RngTgt = DocTgt.Bookmarks("A").Range
RngTgt.Text = ""
RngTgt.Bookmarks.Add "A"
End If