AC3 / DTS passthru problem

[kraney]

My sound card has a quirk where the spdif channel actually goes to the bit bucket, so you have to use the spdif output by sending sound to the default output, and changing a setting so that IEC958 output comes from the PCM. (Realtek ALC850 rev 0.)

I've gotten the workaround to work with most other software, but since VLC detects spdif out automatically, I haven't been able to get it to conform to this. I tried overriding the spdif and iec958 items in .asoundrc, but the VLC doesn't detect them as digital outputs any more, so that doesn't help.

Is there any way I can force vlc to passthru DTS or AC3, but use the default channel rather than the spdif channel?