File output name format

[Mash]

Hi there, is it possible to change the output file name format, at the moment, KS add a sequential number to each file which is outputted, happy with that. However it is usually 'xxxxxx.123.png', I want to remove the first dot and replace with '-' in it format. Usually this file name doesn't cause problems, however, when I bring it into Photoshop and save it as a .psd file, it does it after the first dot. If you have a number of files you loose the number reference. Just a pain.

Thanks Mash