How to Update multiple records from a Multi-Select lookup field

How to Update multiple records from a Multi-Select lookup field

Hi Everyone, 

Ive got a form built to intake information on incoming samples. This goes to factories.

Ive got a second form for my employee who is supposed to select a Date, a Shipping Carrier, input the Tracking Number and the multi-select all the samples that will be included in that shipment. 


For the multi-select im using a lookup field from Form2 to Form1

I want to make a workflow that will take each item selected in the multi-lookup and the tracking number that was inputted in Form2 and add it to each individual record of the items selected. 

I already have a spot left open in Form1 to receive this info.

So basically:
for each item selected in lookup field in Form2, add tracking number to original record in Form1

Any thoughts?