We are using SharePoint Enterprise 2013 On-Premises
I have a procedures library and I would like to have a column called 'Code' so when a document is uploaded a value is added to the column for example
P100-1
Then when a another document is uploaded it will get
P100-2
I am trying to replace the system we have that is currently in a file share

The Code and document title will be separate pieces of information in SharePoint
– Matt Saunders Jan 09 '16 at 09:48We do not need the unique number attached the document title in SharePoint we want the unique number assigned in a column associated with the document
– Matt Saunders Jan 09 '16 at 11:20