non-shared tshark preferences

Hi, Tshark uses the same search path as Wireshark to look for preferences. But sometimes I'd like to let Tshark use a completely different setting, typically prepared in a temporary file, without interfering with the system- or user-wide Wireshark setting. Is that doable ? (one would expect an environment var or an option for this; none seem to be documented)

Thanks in advance,

-Alex