External_Function FunctionName "FunctionName" DLLName {Parameters ...} Returns DataType
    #IF !Zk=0
      EXTERNAL$FUNCTION $54C LOAD_ON_USE GET_ !1 !2 !3 !4 !5 !6 !7 !8 !9
    #ELSE
      EXTERNAL$FUNCTION $54D LOAD_ON_USE GET_ !1 !2 !3 !4 !5 !6 !7 !8 !9
    #ENDIF