Excel Workbook Feature Enhancement

We are seeking a skilled freelancer to enhance an existing Excel workbook by adding new features. The ideal candidate will have experience with Excel and related tools to improve the workbook's functionality. The project involves an existing workbook with 4 worksheets. We want to - Sheet 1 to have a submit button. When the Submit button is clicked, it locks the sheet (only sheet 1) and if possible saves a pdf copy of the worksheet. - Sheets 2, 3, 4 & 5 need to be hidden. Each sheet needs to be unhidden with a seperate access code. - A master code to protect the whole worksheet so that selected cells are always locked. - The workbook will have added formulas and links between sheets added at a later stage.