BACKGROUND INFO: 

I have a form dense with scripts and formulas, lets call it JOB. 

Another form called INVOICE is populated with information from JOB. 

In order for an  INVOICE form record to be correct, one has to make sure the JOB form record that will feed data to the INVOICE form record is up-to-date. 

Currently, to make sure an INVOICE form record is correctly populated with up-to-date JOB data, one has to manually open its matching JOB form record in Edit mode and then click Update since JOB form has OnEdit-OnLoad scripts that in turn pull information from other forms such as TIMESHEETS and MATERIALS.

I want to improve my app design so that in the early stages of INVOICE form record creation when the Lookup Field "JOB" is used to select a JOB form record, an OnUserInput Script triggers an update of the selected JOB form record by essentially running the JOB form  OnEdit-OnLoad  scripts and then Updating that record before any further process of creating the new INVOICE form record is completed.

QUESTION:

Is it possible to call a function that opens a form record in Edit Mode and then Updates that record?

If yes, what is the basic structure ( stateless form? OnUserInput script?) and what code is available to do such a thing?