You really shouldnt be using a repeating field for this. You should be storing it in a join table that links the site and projects table.
I suggest using repeating fields for utility purposes but not for true data.
However just to answer your question, you can specify the repetition that you want to set when you are choosing to specify the target field in the script step.
Also you can write a loop to check the next open rep.
P.S. Why is this in the server forum. Mod please move to correct forum.
I have not done this before. So if I may I would like to check whether I am doing this correctly. In the end I would have three tables PROJECTS, SITES, and JOIN. JOIN has a primary key related to a foriegn key linking the other two tables. Is this correct?
The join table will have its own Primary Key ( Incrementing ), and the foreign keys that store the keys from the other two tables.
fkProjectID and fkSiteID