Is it possible to set the Statsd counter type using a variable?

Good morning,

I am updating my monitoring system and am thinking of changing the way metrics are sent to Graphite and want to use the Statsd output plugin.

The way that the metrics are sent to Logstash is via Redis and the object contains a metric_type which I want to use as the setting in statsd, is this possible? An example of how I think the configuration would look would be:

output {
    statsd {
        host => 'graphite.local'
        %{metric_type} => [ "%{plugin}", %{value} ] 

Would this work? I am assuming that it would not as the keyword is static but I wanted to check.
If it would not work like then I would have to look at using an IF expression which would be OK, but this seems neater.

Thanks very much,