SUMMARY
The command used to access information stored in nonstandard message
types is as follows:
msmail (getHandle, messageRef, ident [, index]) => handle
It is similar to getField, except that it returns the field data in a
handle. The data can then be stored in the stack's resource fork with
an addMacResource call.
"messageRef" is a reference to a selected message obtained by making a
call to the msmail function using a parameter that returns a message
reference.
"ident" is a four-character type identification for that handle, such
as "ICON", "CODE", "snd ", etc.
"index" is a number that directs the command to access a particular
occurrence of the specified field.
When the handle is not going to be used again, it should be disposed
of with the disposeHandle function.
This information is taken from the "Microsoft Mail HyperCard Interface
Documentation."