Use C# to fill a form and save it

I have a pdf form created by someone else (for example, a government w9 form). I have a C# application that knows all the information needed to fill the fields in that form. What API or tool or product will let me automatically fill the fields with the correct data and then save that completed pdf file with a specific filename? Additionally, could C# then open the completed form to allow the user to visually verify the information and make corrections?
I suspect I need to know the field names in the pdf form. How do I determine those? I might even be happy with an alternative solution where the user must click some kind of import button on the blank form and I could provide a tab delimited (or csv) file with one row of data for that user.
 
Hmmm... no one has responded so let me try asking a similar question. There is a product called iTextSharp which can solve my problem. I would rather use a true Adobe product. What Adobe product or SDK includes functionality similar to iTextSharp?
 
Thanks in advance for any replies (even those which might suggest another forum).