How to make Lightroom, to set correct white ballance in infrared photos...
(tested on Adobe DNG Profile Editor version 1.0.0.39 beta 2)

You can use any RAW file (it doesn't need to be IR photo, we just need to create a preset), convert it to DNG format (this can be done in Lightroom), open the DNG in Adobe DNG Profile Editor (can be downloaded for free), on the third tab set White Balance Calibration Temperature slider to "-100" and save it as your own IR preset (a file with .DCP extension). Then the DCP file save here:

for Win7: C:\ProgramData\Adobe\CameraRaw\CameraProfiles\

for WinXP: C:\Documents and Settings\All Users\Application Data\Adobe\CameraRaw\CameraProfiles\

That's all. No other alchemy needed.

In Lightroom I set User Develop Preset for IR photos, so that  Camera Calibration uses my own IR preset. Right during the import (it's possible to do it afterwards as well) I use this User Develop Preset and then I can make the WB as I want.

Warning: While creating the preset in the DNG Editor I don't recommend to make any colour and contrast changes. It is better to make the changes after importing the photos into the Lightroom and applying our IR preset. Presets containing contrast and colour changes produced ugly colour artifacts in some photos. The WB Bias correction is enough.