datadog cannot arbitrarily glob metric names at read time, i.e:

sum(nsq.topic.*.channel.*.message_count)

Instead, it offers you the ability to "tag" metrics. Unfortunately, metrics must be tagged (and re-written) at write time to be able to slice in the dimensions you want.

ddstatsd is a UDP proxy that takes a JSON configuration file with regex-based rules to rewrite incoming metric names and add tags, outputing to the local dd-agent in its custom statsd format.