How to create macro for replacing part of sentence in custom properties

Hi all.

I have a problem and all the time i am doing it manually. I am losing a lot of time for this so maybe there is faster way to do it. I have found similar subject but without final solution: . I have tried to edit this macro and run it but without any result.

I need macro for finding sentence "-_" and replacing with "-XXX_" in custom properties (*.SLDPRT and *.SLDASM files). It would be nice to update the date ("Design Date" in custom property) also but it is not necessary. The XXX is always different for next assembly. I make few assemblies per day. I attached one file with custom proparties for tests.

Here is an example:

Before change:     Custom propertie name: "Part number", Value: "NC-G-05-_318"

After change:        Custom propertie name: "Part number", Value: "NC-G-05-308_318"

Is it possible? How to make it? And finally: how to use it for all files in folder (with subfolders)?

PS. I am using SolidWorks Professional 2015 SP5.0

SolidworksApi macros