How to set up a 'not' control input definition from the tab menu?

[Popcorrin]

Does anyone know how to set up a control definition from the in-game menu so that for instance, player 1 button 1 is left ctrl but it will not work if key_b is also pressed.  The definition would look like  P1 Button1    Left_Ctrl not B.  I know how to set this up in the ctrlr ini files in regular mame but I am trying to set it up in advancemame and after reading thru the docs I have been unable to find a way to do this.   Thanks

[SirPoonga]

mameworld.net/easyemu

I believe they show you how there.

[Popcorrin]

I already checked there.  They explain how to do it via the ini file method but not from the tab menu.   
 

[Thenasty]

select the target
then push Left_CnTRL followed by 2 quick B's.