excel for morgtage

I am looking for an Excel expert who can help me create an advanced mortgage calculator. The specific tasks for this project include creating an amortization schedule and incorporating the ability to add extra payments.

Skills and Experience:
- Strong proficiency in Excel, particularly in creating complex formulas and functions
- Experience in creating mortgage calculators with advanced features such as amortization schedules and extra payment options
- Attention to detail to ensure accurate calculations
- Ability to work with provided examples and incorporate specific format/design preferences into the mortgage calculator

If you have previous experience with creating advanced mortgage calculators and can provide examples of your work, please submit your proposal.