Action Rules

Hi guys,

I want to take a substring (to the comment field) from the %_folderpath% for example using the following Action Rule:


But all I ever get is the full folderpath - never without the last char (which happens to be a \

This is a simple example of what i want to do, easier to write this...

How do I do this in Actions rules..

Many thanks in advance,

math operations must also be made with functions: