Hi:
Check the following documents:
LabVIEW Code Interface Reference Manual (LabVIEW 5.0 or earlier)
http://digital.ni.com/manuals.nsf/caba5d53e9b015a186256793004eebb7/0f3cef1157b9d13f8625665e006358ae
Using External Code in LabVIEW (LabVIEW 6)
http://digital.ni.com/manuals.nsf/caba5d53e9b015a186256793004eebb7/4f1447f7cd83d6d88625690d00637ced
Feel free to ask if you have any trouble with an specific step while creating the CIN.
Best regards;
EJV
www.vartortech.com