I have an excel file containing some stocks.

I have an excel file containing some stocks.1.) I need to add a command button to this excel file using VBA, which on getting clicked would open a user form; asking the user to choose a number "n" between 1 and 500 and a value, "lambda".2.) After this the VBA code, will call a program in python (or VBA code itself) to compute the average returns and the covariance matrix of these n selected stocks and create a text file containing the covariance matrix in a particular format, which I will share with you.3.)And Finally the third step, the VBA code will call a C program to read this text file and use an algorithm to solve the mean variance optimizationI will share the excel file, text file (for the poarticular format) and the C program (which needs to be altered a bit).I will share the files later after seeing your proposal