* CS-PICK ( 2a 2b 2c ... n -- 2a 2b 2c ... 2a )

pick a value in the compilation-stack - note that the compilation
stack _can_ be seperate in some forth-implemenations. In PFE
the parameter-stack is used in a double-cell fashion, so CS-PICK
would 2PICK a DP-mark and a COMP-magic, see PICK

FORTH/ANS tools (dpANS15.6.2.1015) ordinary primitive