Yes the \.* was a mistake.
The expression is was looking for was .*crim.* without the backslash
This worked but for the point that "tags" is a field with mulitble values. So only the value where the string is found will be changed. All others will be copied in the new field.
Is there a way around it?
I dont understand your hint with the tag editor. I don't wont to remove a tag. I just want to use the tags to get my collection into shape by sorting the books to genres like: science fiction, fantasy, etc.