[Question] Can one use tag transform to concatenate tag values?

[bmffb]

Regarding the mapping of bus stops: I would like to combine the value of the "name" tag of a bus stop with the value of the "route_ref" tag into one new tag. The result should look like "name (route_ref)". Does anyone know if and how this would be possible by a simple tag-transform rule?

The question regards to my "mapsforge" map-project "OpenOutdoorMap".