develop a web app involving debt-reduction financial (spreadsheet) calculations

Goals: --create web application that runs formula in attached excel worksheet using data entered in the form, to produce exact same result as the excel worksheet. --the results are estimated amortization tables adjustments that are real estate/debt related. --involves program to help people reduce their debt --need admin section where I can work with the collected data certain rules for the management of the data should be applied (as in what can be edited and what not from what type of users). --Administrator , agents, and users can log in with different privileges when it comes to edit the initially given information on the form. There'll be three roles: 1) the client who submits the information 2) the agent that helps the client with the submission of the information 3) the admin After the form is submitted, client will have access to some fields, but not all. Agent will have access to only a few fields. Admin will have edit access to all fields. You'll be given the PSD/HTML/CSS/Js files. Open to other frameworks, but lean toward WordPress maybe using: 1) gravity forms for user submission of data, 2) posts to represent each form submission and 3) custom fields to represent the data fields within each form as well as the calculations derived from those submissions (using mathematical formulas that correspond with the spreadsheet format) and using custom fields adjusted with the custom field template plugin to make the look correspond to the spreadsheet table format. But I'm open to whatever makes sense and is most time-efficient. In your first message please mention if you've done this before (and have examples) or at least have worked with coding in spreadsheet-like mathematical functions like these. Expert guarantee not necessary, but it would be a positive sign.