I slapped together an excel spreadsheet to do that (on the 2nd tab)
Plus there is a calc to figure out what you need to train in skills to get a level, after being modified by your items. pretty handy in planning things out.
it would be nice if we could add a database of items and use drop down tabs to select the artifact used to calculate resists. but for now its all by hand
pm me an email address, I tried uploading the file as an attachment but it wont let me