Change Icon Text

Hi All,
When we ever we hover mouse on a Icon OTM displays the text associated and we this comes form the Label.xxx for that Icon.
I want to know can we change this as per screen.
Order Base "N" Icon text should be "ADD Order Base"
but same Icon "N" in Shipment should be "Add Shipment"

Can we do this dynamically from front end or we need to change XSL
Thanks,
bscyadav