RTF to PDF

I need to convert an RTF file to a PDF on in a vb app. The
current way is to use the RTF control to change the RTF to TXT
then shelling to a shareware(txt2pdf) to convert it to a PDF.
The problem with the current way is that the RTF to TXT will loses the format.
I do have Acrobat 4.0 but I can't seem to figure out how to call the PDFMaker.
Any help is appreciated....