Xkb Compose:combining_belowdot

[Ruben Porras]

Hello,

I am trying to get some characters with a dot under it (for example ạ). 
Seeing the compose tables tables I came to the conclusion, that it could 
be achieved normally with the combination

<combining_belowdot> letter

As I could not find these symbol under the US or DE layouts, I tried to 
map it using xmodmaprc:

something like this:

cat .xmodmaprc

keycode 48 = combining_belowdot

and I got the error

xmodmap: .xmodmaprc:1: bad keysym name 'combining_belowdot' in keysym list
xmodmap: 1 error encountered, aborting.

Then I tried with 'abelowdot', and it worked.

So, how can I get the combining_belowdot symbol? I read that the symbol 
that you get depends on the locale, how can I find it out? Or I'm trying 
the wrong symbol?

Thanks.