uVision2 Debug Fn: Access to Extended Registers

I am using a Triscend TE505 (with 2 Data Pointers).
In addition to the standard set, the debugger Registers window adds the following under 'Sys':

Sys
 |
 :
 +--auxr1
 |
 +--dptr
 |   |
 |   +--[0]
 |   |
 |   +--[1]
 :

I assume that 'auxr1' is the Triscend DPS (Data Pointer Select) register.

The Function Editor does not recognise these names:

FUNC void ShowRegs( void ) 
{
    :
    printf( "  %02x", AUXR1 ); 
______________________^
*** error 34, line 18: undefined identifier
    printf( "%04x", DPTR[0] ); 
*** error 46, line 19: subscript requires array
    printf( "%04x", DPTR[1] ); 
*** error 46, line 19: subscript requires array
    printf( "\n" );
}

So, how can I access these extended registers from a Debug Function?