[TYPO3-mvc] how to set pid of relation via cli

[Thomas Mammitzsch]

hi list,

i have an scheduler task which does importing/updating via extbase.
I know that there has to be the pid defined in $TCA in order to use the 
setPid()-Setter successful.
But how do i set the pid of a m:n relation?
I'm using extbase 1.3 (Typo3 4.5).

Example:

An Entity tour has one or more entities employer assigned which are 
responsible for that tour. I can set the pid for the tour and the 
employer to the storage pid, but how can i set the pid for the relation 
(means in the relation table)? The relation is made by 
$tour->addEmployer which simply attaches the employer object to the 
object storage. The pid is 0 because it doesn't get set.

thanks and regards, Thomas