Access BO from another BO

Hi all,

I have a script in the BeforeSave event under sales quote root.

I would like to pull some data from a contact related to the quote's account.

I can get the contact id from the buyer party, however, there is no other data in this section which can be helpful for me.

(mainly, I want to access some extension fields i created in KUT)

I guess I should link the BP BO to the Sales Quote BO in some way, but I don't know how.

any ideas?

Thanks,

Dror.