Merging .txt files and performing calculations

I have a folder of .txt files like the ones attached. These fies represent data of stocks in the form <Name>,<Date>,<Open>,<High>,<Low>,<Close>,<Volume> Like in <Name>,<Date>,<Open>,<High>,<Low>,<Close>,<Volume> IBM,20201103,1.0495,1.0495,1.0475,1.049,12 Or say (another stock) <Name>,<Date>,<Open>,<High>,<Low>,<Close>,<Volume> AAPL, 20201103,1537.3,1537.3,1536.0,1536.7,23 Etc I want to develop a Graphical User Interface (a sample is attached) where I will be giving pairs of stocks (say StockA and StockB) and the program will open their corresponding .txt file and produce a NEW .txt file under a name that I will specify (say StockAB) that will look exactly like the original files but OpenAB = OpenA/OpenB HighAB= HighA/HighB ….. etc VolumeAB = VolumeA + VolumeB For every Date, starting from the bottom of the file all the way up (the Dates must be the SAME of course!! If there is a ‘orphan’ date somewhere in one of the files – which I doubt of course – it will just be ignored) Lastly – like in the attached image – there will be a ‘multiplier’ associated with each stock, meaning that all prices (open, high, low, close that is) of this stock will be multiplied by that multiplier, before the divisions take place (default will be number 1). So if, for example, I set ‘100’ for IBM above, it won’t be 1.049.14 / 1536.7 for the ‘new stock’ IBMAAPL, but rather 104.914 / 1536.7 All .txt files of these ‘new’ stocks produced this way, will be placed in an output folder I will designate in the GUI No bids above $100 for this will be taken into consideration.