It's all in the panel!
1: Make sure to add the TDS specific subdirectories (EXT_TEXTURE_ANIM, Tds_util and Tds737ADVCONTROL) to your panel folder.
2: Add a window entry for TDS utility to panel.cfg:
[WindowX]
VISIBLE=0
position=2
size_mm=298,104
child_3d=0
background_color=0,0,0
ident=Utility
gauge00=Tds_util!Tds_Init, 0, 0
gauge01=Tds_util!Tds_Timer, 0, 0
gauge02=Tds_util!Tds_Util, 0, 0
Add Vcockpit entries to panel.cfg to initialise TDS stuff:
[VCockpitXX]
size_mm=512,512
pixel_size=512,512
texture=$Posky_ACU
background_color=0,0,0
gauge00=Tds737ADVCONTROL!Tds_AdvInit, 140,80,140,80
gauge01=Tds737ADVCONTROL!TdsAUX, 140,80,140,80
gauge02=Tds737ADVCONTROL!TdsRudder_Elev, 140,80,140,80
gauge03=Tds737ADVCONTROL!TdsEngRev, 140,80,140,80
gauge04=Tds737ADVCONTROL!TdsWingflex, 140,80,140,80
gauge05=Tds737ADVCONTROL!TdsNosegearsteerling, 140,80,140,80
gauge06=Tds737ADVCONTROL!Tds_Spoiler, 140,80,140,80
gauge07=Tds737ADVCONTROL!Tdsflasher, 140,80,140,80
gauge08=Tds737ADVCONTROL!TdsSEA, 140,80,140,80
gauge09=Tds737ADVCONTROL!Tdsgearheight, 140,80,140,80
[VCockpitXXI]
size_mm=512,512
pixel_size=512,512
texture=$EXTANIMBASE
background_color=0,0,0
gauge00=EXT_TEXTURE_ANIM!EXTTEST, 0, 0, 512, 512
(Specifically, without "Tds737ADVCONTROL!Tdsflasher" the flashing lights won't work.).
The contents of the panel subfolders and the vcockpit entries are slightly different from model to model, make sure you get the proper ones from the right FSX model package, can be downloaded from the TDS 737 Facebook group.