Thanks to the help of hardoff and pulsed my patch is finally working quite well when I run pd from the command line using

sudo pd -rt -jack -channels 2 -send ";pd dsp 1" open /some/file.pd

However, I do not get how the -send option is acutally used. The documentation only states.

-send "msg..." -- send a message at startup (after patches are loaded)

How can I specify where the message is received. I have tried a receive node [r something] and the comand line option -send "something; 1", hoping that the "1" will be received.

What I want to to is to send a number to a specific node in my patch on startup.

its -send ";somewhere 32435''

semicolon before the receiver name.

seems I was wrong here.

Theres no need for semicolon in the -send message.
But:

to make -send send to a receiver in a patch the -open message has to be used correctly.
that is not just somepatch.pd or open somepatch.pd but -open somepatch.pd.

eg -open somepatch.pd -send "somewhere 11"

my bad