mciSendString for volume

[curry]

I'm trying to set MIDI volume on Windows so that my stack can control 
the volume for playing .mid files when not using QuickTime.

I looked for info on mciSendString and was successful in playing a 
file, but haven't been successful in finding volume.

Here's the all-purpose handler I use for trying the commands:

on mci x
  replace "/" with "\" in x -- convert any Rev file paths to Windows
  get mcisendstring(x)
  answer it & cr & the result
end mci

The following commands don't work:

mci "status sequencer volume"
mci "set sequencer volume to 30"

I did get it to play a file, with file path stored in a field:

mci "open" && quote & field "file" & quote && "type sequencer alias mid"
mci "play mid"
mci "status mid position"
mci "close mid"

But also volume didn't work:

mci "status mid volume"
mci "set mid volume to 30"

(There I tried using a specific file just to see if it worked, but I 
would prefer setting volume for the device rather than a file.)

Does anyone know the proper way to do this?

Thanks very much,

Curry