Concentration duration and moving targets

[Jonathan.Link]

It depends...

@Ars Magica 5th Edition

A spell that has a continuing effect remains in effect even if the caster moves out of range. A spell that allows the caster to control the effect only permits that control as long as the caster is within range.

What needs to be determined is if it is a continuing effect. I think it is for as long as he concentrates.