I have a program running in the background of my pc.
I'm looking for a way so that I can execute one of my functions at a specific time of the day, is it possible to 'hook' into the windows time events or something ? I don't want to have to add an entry into the scheduler.

When I had a similar situation, I did it in this way.

The client was having a dedicated server.

I requested them to open a page in a browser always in any machine (if possible on server itself).

That page used meta refresh which will make it reload every one hour.

I checked in that page whether the task is done for current hour. If no, I will do it and record the time in a log file.

This is working without any problem for the past 2 years.

If the program runs already you don't need the scheduler or anything. Just check in the program from time to time whether it's time to run that task. Just make sure you
  1. do not run the task twice jus because it finished quickly and it stil seems to be the right time to run it
  2. do not skip the task just because the application was busy at the scheduled time.

Which means you'll need to remember the last datetime it was run and you'll check whether the current time is after the scheduled time and the time of the last execution before the scheduled time. Or something like this.

It's hard to be more specific without knowing more about the design of your program.

Oh my gosh.
If all you have is a hammer all problems start to look like nails, rigth?

This is very awkward solution and let me tell you something, if a consultant (or whatever you want to call the person) suggested something like this I would know I need to find another.

Even if you do stick to VBScript you can do much better.
Do rewrite the "program" so that it works from within Windows Scripting Host (wscript/cscript, see microsoft.com) and have it scheduled at the rigth time each day.

Hello Jenda,

I agree the above method is not the best one. The best method is to do it in VBS and put it in scheduler. But the poster ginoitalo had said he cannot put anything in the scheduler. Haven't you noticed it ?

The answer should be suitable to the particular situation in which the person is. If you know any other method other than VBS and meta refresh, then post it.