Embed objects in RTF?

Can somebody tell me how it works to embed
objects (such as winword files) into a RTF file?
The problem arises on building a RTF file from a mail:

*** Given ***
1) RTF text with the positions marked where the attachments (=objects) should appear.
2) Object files (e.g.: winword.doc)

*** Wanted ***
RTF file with the objects embeded?

Thanks a lot in advance ...