vmpsplugin.php overwrite, how?

[ptrouw]

I tried to use overwrite but this doesn't seem to work with /administrator files, as fas as I know.
In this file:
administrator/components/com_virtuemart/plugins/vmpsplugin.php
Line 784:
$costDisplay = '<span class="' . $this->_type . '_cost"> (' . JText::_ ('COM_VIRTUEMART_PLUGIN_COST_DISPLAY') . $costDisplay . ")</span>";

There are brackets used. I don't think they should be hard coded. Payment for shipping costs, are real, why but them between brackets!

[Milbo]

In the moment you create a plugin, you can overwrite almost any function of the parent class.