[asterisk-dev] 1.6 - beta9: channelvariables.txt missing

[sean darcy]

I'm trying to set CALLERID(num) if the calling number is less than 140. 
Thiat is, for all the internal extensions less  than 140, I want to set 
the main number as the callerid, but use DID for 140 and up.

So I tried:

exten =>_1NXXNXXXXXX,n,Set(CALLERID(num)=${IF( $[${CALLERID(num)} > 140] 
? ${MAINSTUB}${CALLERID(num)} : ${MAINNUMBER} )})

But I get this error:

  [Jun 20 11:40:24] WARNING[7821]: ast_expr2.fl:398 ast_yyerror: 
ast_yyerror():  syntax error: syntax error, unexpected '>', expecting 
$end; Input:
  > 140
  ^
[Jun 20 11:40:24] WARNING[7821]: ast_expr2.fl:402 ast_yyerror: If you 
have questions, please refer to doc/channelvariables.txt in the asterisk 
source.

Now I think the problem is that CALLERID(num) is a character value that 
can't be compared to another value. But there's got to be some way to do 
this, so I looked for channelvariables.txt. It's not there.

So any help on my specific problem would be appreciated. Or if I should 
RTFM, please point me to the FM.

Thanks.

sean