Hi Kate,
A solution which comes to mind is using Metacourses.
This means that you create a metacourse for your Newsforum to go into and then you enrol your courses of one of the learning programs into the metacourse (as you can only enrol courses into Metacourses and not students 
).
When you post in the news forum, all the students who belong to that learning program will receive it.
More info on Metacourses can be found here and Scenario 1 has a explaination and great picture which probably explains it better than me
i would like to say , this category meta link , started working ?, which link shows the steps , which will be more ideal , because than adding each course , if the category at a stretch added , it reduce a lot of mechanical work. ok, could u answer my question also