Having looked at the admission arrangements on their website
http://www.parmiters.herts.sch.uk/welco ... sions.html
it seems a very complicated mixture of proximity, siblings and musical/academic ability within
specified postcodes. It looks as if the only guaranteed way would be for one parent to have an affair with the parent of a current pupil and move in with your daughter thus creating an instant sibling.... (sorry, only joking!) Seriously, if it doesn't seem like you have a realistic chance of success, there is no way to "lobby" if the school is already going to be filled with pupils who do fit the criteria more closely. There must surely be other schools within reach that have a reasonable number of bright children, or selective schools without such strict location criteria. Or you could move to Solihull!