I am looking to have an Excel spreadsheet modified/programmed. We have used a single Excel file for >20 years as our database to track treatment and outcome of patients. It currently has 5700+ rows with 43 columns of data per row. We would like to modify the spreadsheet so that is it more efficient to enter data into each of the columns by using dropdown menus for many of the columns. There are also some columns that need to be modified such that an entry into one would prevent an entry into another one. We are hoping to make the data entry process less error-prone. We would also like to be able to query the spreadsheet without having to use separate database software. Currently, we go through the onerous process of filtering columns to get lists of patients with particular characteristics from which we can analyze the data. Ideally, we'd like to have our current Excel file modified with VBA so that it can stay within the same Excel file.