Hello Cesar!
Page 31, under 5.0 Fire Combat
If a Good Order Leader (11.1) of the same nationality/color/IB is present, his Leadership Modifier (LM, 11.1.1) is subtracted from the DC roll of the other units in the hex (not himself). The Leader must survive his own DC first, and be in Good Order, before aiding the other units in his or her hex.
Page 67, under 11.1.1 Leadership modifier:
A Good Order (GO) Leader’s Leadership Modifier (LM) can be used to:
...
• Modify (is subtracted from) Damage Checks (5.0) by all Leg units in hishex.
Page 72, under 11.8 Chaplains
Chaplains have a Leadership Modifier (LM, 11.1.1) just like Leaders, but their LM can only be used to rally Shaken MMCs or SMCs in their hex;
they cannot be used to assist Damage Checks or assist in fire attacks (5.0).
Page 141, under Single-Man Counters (SMC)
Leader’s LM is a measure of his (or her; there are some tough female Leaders in the Viet Cong and the Soviet Partisans) Leadership and ability to influence fire combat, Damage Checks (DCs)
So yes, it is used
There is no such thing as a DCT (yet) but I like the idea of calling that table Damage Check Table, without specific reference to the DFT (because Ordnance fire attack can also lead you to use this table)