The DEFAULT option works as you described, but you'll need to set @path this way if you want to pickup all default trace files:
SELECT @path = REVERSE(SUBSTRING(REVERSE([path]), CHARINDEX('\', REVERSE([path])), 260)) + N'log.trc'
FROM sys.traces
WHERE is_default = 1;
There are no special teachers of virtue, because virtue is taught by the whole community.
--Plato