I used a batch file method with the speedset program rather than imbedding in the VDMS Launchpad autoexec because the game would hang and I couldn't get the right value for speedset with the latter. Here's what I did:
Copy Speedset files to AITD3 folder.
Go into MSDOS Mode (Command Prompt in Start Menu Programs).
Go to game directory (for me it was c:\i-motion\indark3).
Edit new file AITD3.bat as follows:
speedset -30
aitd3.exe
Exit MSDOS Mode.
Go to game folder.
Delete any VDMS shortcuts.
Right-click on newly created batch file and 'Run with VDMS', using all
the VDMS properties necessary for sound and voice.
When you run the game, you'll notice slow fade-ins/outs of opening
screen shots, but when you enter the game...no noticeable
slowdowns and Carnby should run ok.
Good luck.