thanks a lot for the help, it could be a viable way that surely helps. It was not what I wanted but I guess that there is nothing else that can be done. At this point I guess that there is no way to read a text string contained in the Gcode from a macro

You can write a VB macro and run it using the VB Editor launched from the "Operator" menu.  The functionality is then up to you - it might for example read data from an exported CAM tool table and write it to the M3 tool table.

I tried to run the export and import scripts but I couldn't get them to work.. could you explain to me how to use them?

As they are written in Cypress Visual Basic they need an appropriate runtime environment to work, they are not compatible with for example Microsoft VB as far as I know.  Such an environment is built-in to Mach3 to run its scripts (macros) and wizards, either OEM or user-defined.  It's a while since I used these but IIRC you open M3 and then a Script Editor window as in my last post.  Open the script in the window, then either "run" it from a menu or by pressing the green arrow.  Everything happens very quickly for the import/export scripts.  For export for example it exports a text file to the top level of c\mach3\  called ToolTable.txt.  You should then see a message in the Status DRO of the Program Run screen saying something like Tool Table - [N entries exported]  If you want the file to be somewhere else you need to edit the file path in the statement

textFilePath = "C:\mach3\ToolTable.txt"

which is near the start of the code.

I had already tried to execute the file in the way you described before writing to you but when it exports it creates the file but it is empty..

Have you checked the file using the tool table editor? Maybe it is empty. I have used this export function and it worked well.

IT WORKS THANK YOU SO MUCH I PROBABLY DID SOMETHING WRONG

Excellent, happy to help.