add_hdd dont working

hii

I used DAEMON Tools Pro Standard 6.
I try to create new removable device with cmd commands, first i try it with the application but I need to use it from my code - so must use cmd.
I send:
DTAgent.exe -add_hdd K, "C:\test.vhd"
and get error window:
add_hdd switch syntax error

sombody have any idea what i do wrong?

another question - there is an api for c# that I can use daemon tools from my code without cmd?

tnx!!:D