Hi Priti,
Collate complete data in one excel file and prepare a pivot table by employees, there expenses & Aging analysis.
It will give you employee wise details grouping in ages(<30 Days, 30-60,60-90,>90 Days )
Please let me know if you have further doubts else provide me the sample expense sheet I will send you with a prepared report.
Warm Regards,
Vinodkumar Gandhe.