Currently, the EXECUTE PROGRAM action is one-way. You can execute a program, but there's no way of capturing the output from STDOUT. I know you can do convoluted workarounds like having the program write the output to a file, then importing the file, but it shouldn't be this hard.
We should be able to directly capture STDOUT in query string format or JSON and the action should create an instance of a specified BO, in much the same way that EXEC SP works.