Generating a number to be passed into a map

From: RichTheHSTGuy (RichTheHSTGuy_at_discussions.microsoft.com)
Date: 11/03/04 

Date: Wed, 3 Nov 2021 08:33:04 -0800

I have a map setup like below mapping multiple companies into a schema and
generating 1 instance of each in my destination schema, 2 comapnies 2
instances(this works great because of all of the help on this board). What I
need to do is generate an ID number for each instance and map it to a field
called set-id in the destination.
 
Source Schema

Company1 name
company1 number
company1 address
Company2 Name
Company2 number
Company2 address

Destination Schema

Set-Id
Company Name
Company Number
Company Address