Well, unfortunately not quite. The VB rich text box does not support all the formatting features used by Word, so it would only be a close approximation.
If you've got Word and Acrobat 5, it would be better to automate Word, and get Word to print to PDFWriter. Something like the following:
Option Explicit
Private Sub Command1_Click()
Dim myWord As Word.Application
Dim myDoc As Word.Document
Dim OriginalPrinter as string
Set myWord = New Word.Application
Set myDoc = myWord.Documents.Open("your_document_name"

OriginalPrinter = myWord.ActivePrinter
myWord.ActivePrinter = "PDFWriter"
myDoc.PrintOut
myWord.ActivePrinter = OriginalPrinter
myDoc.Close (False)
myWord.Quit
Set myWord = Nothing
End Sub