Use ColorPerfect, a Photoshop plug-in to use with your neg scans that matches colour accurately to different film types. Itís not very user-friendly program to set up, but worth sticking with as results are excellent.
http://www.c-f-systems.com/Plug-ins.html

Here is more info:
http://www.colorneg.com/oldneg.html?lang=en
and
http://www.flickr.com/groups/colorperfect/