This is used to list the subkeys of the opened key.
xcall MIAMEX,MX'REGISTRY,5,hkey,subkey,index,status
hkey
must be set as in opcode 3 (Set)
subkey (string)
will return the subkey name.
index (numeric)
should be set to 0 for the first subkey, and incremented for each subsequent subkey. There is no particular order to the subkeys, so do not put any special significance on index.
status (f,6)
0 for success, else error code. Error 259 indicates that there are no more keys to enumerate.
