Pass numeric value to other running exe using VB.NET

You are going to have to be an awful lot more detailed about this - you are just far too vague with the question to get any real help.

Start by thinking about the two applications: does your app start the other? If it does, you may be able to pass the value via a parameter string when you start it.
But even that depends on the other application understanding what it's supposed to with the parameter, which is by no means guaranteed.
Or it might expect you to talk to it via a socket - in which case you need to know how to talk to it, what commands it accepts, and so on.

Or the app may be a spreadsheet , and you want to update it's files, or modify it's data while it is running - both of those need special handling.

Or ... you get the idea. We have no idea what either of your apps do, or how they work. So start with the app you aren't writing, and see what you have to do to talk to it - then think about how your app needs to be coded to do that!

Sorry, but we can't do any of that for you!