Run a batch file from Processing

Processing Electronics (Arduino, etc.)
2

I found that running this line from the sketch:

launch("rundll32 SHELL32.DLL,ShellExec_RunDLL " + "C:\\Users\\sknippels\\Documents\\hobbyProjects\\functionBloX\\flashArduino.bat") ;

actually launches cmd.exe and runs the script. But now there is something wrong with the paths. + i would like to use relative paths.

Inside the batch files I have this content. I just invoke arduino-cli.exe 2x

echo off

Arduino-cli\arduino-cli compile -b arduino:avr:uno .\arduinoProgram
Arduino-cli\arduino-cli upload ./arduinoProgram -b arduino:avr:uno -p COM4

pause

When double clicking it from the explorer, all is well. But when running the line with launch

This happens

C:\Users\sknippels\Documents\processing-4.0.1>echo off
The system cannot find the path specified.
The system cannot find the path specified.
Press any key to continue . . .

How do I use a relative path here? The absolute path cannot be used anyways.

Kind regards,

Bas