Retirement Income Spreadsheet

Investment Advisor dealing with prospective retirees. I need a detailed spreadsheet to demonstrate how long their funds will last. Needs to incorporate, rates of return on investments, inflation, ax rates, IRS Required minimum distributions, etc. Will also need to incorporate different pools of assets, etc. I will be able to provide an example of a similar spreadsheet. A VBA or similar interface would be helpful. Or, some means of making data entry possible for administrative person. There are more components to spreadsheet, but this will hopefully provide a general idea of teh project. Thank you.