Let us have a form with a RichTextBox and a Command Button as shown below
The following VBA code will copy the Contents of RichTextBox to the First Paragraph of the ActiveDocument
Private Sub cmdCopyRTFContent_Click()
Dim oRange As Word.Range ' Word Range
Dim sPath As String ' Temp Path
Set oRange = ActiveDocument.Paragraphs(1).Range
sPath = "c:\shasurdata\Temp.rtf"
Open sPath For Output As 1
Print #1, RichTextBox1.TextRTF
Close #1
oRange.ImportFragment sPath
End Sub
The program Exports the contents of RichTextBox to a RTF file and then imports to the Word document