Dynamic variable

I need use dynamic variable:

:local a “b”;
:local $a “My text”; > “$a” represent “b” variable
:log info $$a; > wtite “My text”

Last row don’t work. Do you now how is correct syntax for get value of “b” variable? I need use dynamic syntax (as PHP) $$a - it represent $b variable.

Thanks.

It is not possible.