RTF libraries/classes/assemblies

Hi,

I am using RichTextBox for a windows app. Users can enter
information (text and images) in the RichTextBox, and the
information is saved to the database. At some point of
time I would like to create a report that would
concatenate and programmatically format different RTF
texts. The functionality that I need to have includes
insertion, deletion, text appending functinality as well
as formatting with bullets, adding regular text and
creating tables/cells around some of the RTF texts. The
RichTextBox provides only capability to append RTF and
format selection. In my case, I would like to make it
windowless and have all manipulations performed in memory
and then show the result in the RichTextBox or save it as
a file.

Is there any libraries/classes/assemblies available
for .Net developers with that kind of functionality? If
not, is there any samples that I could use?

Thank you.