I am an Australian business analyst with 15 years professional experience.
In addition to expert level Excel skills, I am highly numerate (I have studied statistics, calculus and discrete maths at a university level), and degree qualified in Finance (and information systems).
I am detail oriented, love working in Excel, have a creative approach to problem solving, and possess an excellent work ethic.
After reviewing your attached pdf I am confident I can build a solution which you will be extremely pleased with using a combination of IF statements to ensure the annulaised withdrawal percentage does not rise above 6.5% nor fall below 4.3%. Just a question - is the withdrawal rate calculated from the principal or the current value?