Auto Fill form data

Hi

I am looking to auto fill a form that we use regualry in my office from our ref book.

This form contains the data of the jobs, each client is given a unqiue ref number and i want to be able to enter the 1st job ref number and the final job ref number in the group but still be able to pull all the data for the jobs in between.

These sometimes have more than one item per job.

the collection of job do have one unique factor other than Ref Numbers to each job they are all in one Box which has a unique ID number that is applicable to all jobs (if that makes sense)

Thanks in advance.