Financial calculators in excel

I will commission the creation of several financial/credit calculators in Excel.

I want to put the calculators on the website so that potential customers interested in taking out a mortgage to buy an apartment can make simulations for themselves. E.g.: difference between decreasing and equal installments, different loan periods, total interest with different loan periods and parameters.

Requirements for the file:

- Branding of the file - placing a logo or web address.

- Placing a watermark - to discourage competitors from using the calculator.

- The file should be protected/closed so that users cannot see what formulas have been applied.

- The file should clearly indicate and describe which fields are completed by the user

- I want to embed the calculators on the site so that users can use it live (zaEmbed the file placed on OneDrive account)

I am looking to collaborate for this and more similar jobs in the future.

The right contractor will be able to:

- Create a calculator based on the source files (I have several versions, I need to make an even better one)

- Process the file in terms of user experience, so that the target users can use it easily

- Advise what elements/diagrams/charts to include in the target tool and how it is presented so that it is easy to read