write an executable file

I need an exe file that can be launced with a variable called %ANI. The variable will contain a phone number. Then, I need to be able to input the value of the variable (keystrokes) into an open program running on a windows 10 or windows 7 PC. There needs to also be a way that I can control which program recieves the value. For example, if my program is called "IMS" I need to tell the executable to bring focus to the program running called "IMS". Then, slelect the phone number field, and input the variable value. This will be used to ultimately pull up a customer record when I answer a phone call. The value of %ANI is created by something else already working. I'm thinking if I can have a txt file on the PC that contains the program name "IMS", I'll have the flexibility to change it if I need to. Also, the phone number field might be named something different in another program so maybe also in the txt file have a field title that will recieve the value of %ANI.