Get the current status for the shift and ctrl keys to a macro variable.
Possible values: 
 0 - no key pressed 
 1 - shift pressed 
 2 - ctrl pressed 
 3 - shift + ctrl pressed
PKKEYSTAT is probably best used with a macro called from an icon. 
 Sample macro:
MACRO KEYSTATSAMPLE  
PKKEYSTAT;key 
ifz;key-1;shifted 
ifz;key-2;ctrled 
ifz;key-3;ctrlshifted 
LINE 
go;done 
:shifted 
BOX 
go;done 
:ctrled 
CIRP 
go;done 
:ctrlshifted 
ARCB 
:done 
endm