Macro to assign unique ID

Hi,

Attached is the excel which has UID as the column name. When i run the macro an unique id should be assigned to each record.
However, unique id should be same for the client name with same 'Plan Renewal Date'. For example in the attached 'R00001' unique id should be assigned to client name 'CEM corporation', 'R00002' unique id should be assinged to client name 'Stabilit America, Inc.'

Format of the unique id should be 'R00001'

Thank you

Renewal-Wizard-Report.xls