exporting a vrscene contains underscore before frame number

[drew123]

Hello,

Maya 2012
Windows 7 OS
Vray for Maya 2.2

I am trying to export vrscene files so that I can send them off to a render farm. In the Translator tab in the File Name box I put:

P:\caches\v001\130_061_lighting_<Layer>..vrscene

The resulting file name looks like:

130_061_lighting_artifact_layer1._0000.vrscene
130_061_lighting_artifact_layer1._0001.vrscene

How do I export the scene file without the underscore before the frame number? it seems as though the translator is automatically doing this even though I haven't specified it.

Thanks,
Andrew