persistent Datagen /w command line automation?

It seems like if you make your data gen test step persistent it will not increment when it is run from command-line.

For example if i already used "TEST-01" when i run datagen it should become "TEST-02"

I think command line will just keep using "TEST-01"... From the UI it will increment to "TEST-02", but from command-line it doesn't seem to behave.

Any ideas?