Automate a linked cell within a record

How do i automate
a PO number imported from excel , so that it automatically copies the same po number and links records cell ,
image

Is there a reason that you’re not importing directly into the linked record field itself?

Also, please don’t post the same message twice. You already posted this same question here:

Scott , thanks for getting back to me , see images below of the proposed automation
your help is much apricated

Scott
it is not allowing me import directly into a linked field

Scott

the automation has worked , ( the exact same automation ) , when i re imported the excel file , for some reason

thanks for your time