you can try cute pdf, but its not free http://www.cutepdf.com/ pdf sdk
from their sample code you will be doing something similar to
Set objMyForm = Server.CreateObject("CutePDF.Document") 'Create form object
objMyForm.initialize("FS20-001-12345678-12345678") 'Initialize object by serial number of the license
'Open an encrypted PDF form file from an URL with password 'cutepdf'
if objMyForm.openFile("ftp://www.ftpsite.com/Encrypted_Form.pdf","cutepdf") = false then
errorMessage = objMyForm.GetLastError()
'Set some value into fields
nReturn = objMyForm.setField("Company", "Acro Software Inc.")
nReturn = objMyForm.setField("Address.1", "Company address")
nReturn = objMyForm.setField("Address.2", "City, State, Zip")
nReturn = objMyForm.setField("Product", "CutePDF Form SDK")
'Save completed form file into a new PDF file
'Save a duplicate copy
which is your normal component usage
Everything you can imagine is real.