Improve the way how Xporter is integrating with Tempo Timesheets

As a user I can define a time interval to load data from Tempo Timesheets.
/plugins/servlet/tempo-getWorklog/?format=xml&issueKey=TASK-2&dateFrom=1970-01-01&tempoApiToken=<my-token-goes-here>
Setting the "dateFrom" Parameter would really help and most likely speed things up here. Any hints on how to set this parameter in the template? Something along the lines of:
New properties must be created and processed:
tempo.date.to
tempo.date.from