Access sequence in partner determination

Dear Experts,

I am trying to customize an access sequence but I am struggeling with the understanding of the functionnality:

- I have got a Sold to Party XYZ that has relationship : For example: Has for Contract Manager "Julie Martin" (which is a customized relation)

- when I create a new contrat based on sold to party XYZ, I would like the relations, such as Julie Martin to be automatically added in the 'Persons/Organisations concerned' assignments blocks.

Would access sequence allow me that possibility?

If yes, could you please help me in defining it? I have tried several test but does not work.

Thanks a lot for your help,

Regards,

Emilie.