Question about anyelement datatype

Hi

I need to use the following statement in a stored procedure:

EXECUTE 'SELECT * FROM ' || v_table_name INTO v_result;

where v_table_name and v_result are the arguments of the function.
v_table_name is of character varying type and v_result is anyelement.

But as I discovered, it's not allowed to write into function arguments.
I also tried to declare v_result like this:

v_result v_table_name%ROWTYPE

but that's not allowed either.

Then I tried to use this:

v_result v_data%TYPE

where v_data is an argument of the same function with anyelement
datatype, but no luck.

Is there a way to declare such a pseudo-type variable inside the stored
procedure?

Thank you in advance,
Kaarel