I have a batch script on my computer called
This is happening because your "cs.bat" runs in a different process (running cmd.exe) spawned by PowerShell (whereas batch files execute in the same instance when run from
cmd). Current directory is a per-process concept, so changing it in one process has no effect on another.
Probably the simplest way to get around it is to write a "cs.ps1" script (or function), that would run in the PowerShell process.