Windows desktop Application

I have .txt file which have list of names with .jpg extension (Eg: CA_002.jpg) and the .txt file is encrypted. now I need a windows desktop application to decrypt the .txt file and move the list of name in .txt document from the "Images folder" to the folder called " selected". It should also have a list box with different image extension (eg: .Png, .NEF) so that we can also move the file Same Name with different extensyion ( Eg: replace the .jpg names with .Png extenstion move same name file with diffrent extetion) I have attached the a picture kindly have a look you may get better Idea.