[NTG-context] \define a command with square-bracket arguments

Hi all, As I understand it, \define[2] is preferred over \def#1#2 because it refuses to overwrite existing commands. \define[2]\mycommand{code code code} defines a command to be invoked with \mycommand{...}{...} Can I use \define, or a related command, to define a command that takes square-bracket arguments, like so: \mycommand[...][...] ? When I type \define[1][2]\mycommand{code code code} that doesn't work. Cheers, Sietse