[Guest]

just to clarify, you mean you are scanning negative film on the scanner?  Which you then have to invert?

 

This web site sells software for the inversion, but actually has lots of technical info how it has to be dealt with:

http://www.colorperfect.com/colorperfect.html?lang=en

Removing the orange mask is not that difficult, but getting the correct gamma curve for the highly non-linear negative is a bit tricky.

 

here some other info:

http://www.jeffreysward.com/editorials/colorneg.htm