Start Debugger "from running program"

[C# Programming]

I have a question, starting the debugger somehow indirectly, in this szenario:

1)
I start a dot-net-executable within a batch-file

2)
When this exe is started from the batch, I want, that the debugger is started "automatically", so that I have the chance to trace the running exe (e.g. by breakpoints)


Question:
How can I start the debugger this way?


Thank you