Record mxf-file with a given start timecode

Hey there,

I tried to record a DNxHD video and set the start timecode to a specific value (e.g. time of day) with the caspar client and a custom command with the ffmpeg command -timecode attached:
ADD 1-34448 FILE "Output.mxf" -codec:v dnxhd -b:v 120M -flags:v +ilme+ildct -threads:v 4 -filter:v format=yuv422p,interlace -timecode 10:00:00:00

The recording works, but not timecode is set. In the log I got the message:
Unused option timecode=10:00:00:00

Is there an option to make this work?

Best regards

Florian