Greetings,
You made my day! I have managed Re-hires, but lacked your interest to formalise it with such an honour. I cant offer you a format, but here's the experience that I gained.
We didn't include the complete Induction Program. Areas including machine learning such as how to use the SAP to request for a leave or claim a reimbursement, were excluded from the Induction program for them, as they already knew it. We used to formally inform the leaders. Most of them would already know, they are rejoining. Hence, call for an informal hurdle or ungrouping than any formal process.
What we primarily aimed through this was, identifying the skills the employee brought in addition to what they had already learnt. For few verticals, such as Business Analytics or development in specific skill sets, they used to call for presentation by the employee. This was primarily to gauge the new information the employee is bringing back and how can it be utilised in the existing systems. This was to be attended by a focussed group.
A leder who used to head a Business Unit, once told me , that re-hire is the ultimate win to why we form employee alumni. Congratulations to you and your organisation on this. Wish you all the best !