How can i lock parts of the form for "Office Use Only"?

I am looking to lock sections of the forms i want to create, so that once my clients submit them i can then do the follow up tasks related to the form. 

for example - someone is submitting a form to request time off of work. I would like to have a locked section at the end of the form (could possibly be a checklist) where i can mark off the follow up tasks that have been carried out once the form was submitted. Once the checklist has been completed, it would then be resubmitted. Is is this possible? I hope this makes sense. 

It looks like your requirements are similar to the approval workflow process, please check the guide below.

Guide: A-General-Approach-on-Building-an-Approval-Process-Workflow

Let us know if you have further questions.