Finding a Specific Driver
You might want your application to send a message directly to a specific driver or to identify certain drivers from the list. For example, you might want your application to identify those drivers that support filters and then query each driver to determine which filter tags it supports. You can use the acmDriverEnum function to obtain a handle to the desired driver or drivers; this handle can then be used to communicate with that driver.
Note that when an application installs a local driver for its own use, the acmDriverAdd function returns a driver handle, which can be used to communicate with the driver. It is not necessary to use acmDriverEnum in this case.