Don't confuse a CIN (Code Interface Node) with the Call Library Function Node in which you interface to a dll. A CIN is a c language function only. The Call Library Function Node can be used for any dll in which the parameters and calling conventions are something LabVIEW can handle. You can create these dll's which c, C++, VB, Delphi, etc. The pdf document "Using External Code in LabVIEW" that is part of the shipping documentation explains the differences between the two. You can also find app notes and example code
here that might help.