Unable to pass dynamic parameter values in insert statement

Hi,

We are doing truncate load for around 50 tables. We have created one table which will have all the information of the tables like schema name,database name, table name etc. We are passing these values as dynamic parameter to exeute sql task.
But the problem is it not accepting the dyamic parameter values that is :-

INSERT INTO ?.?.? SELECT        *  FROM  ?.?.?

But this query is working:-

insert into dbo.dummy
(parm1,
parm2,
parm3,
parm4,
parm5,
parm6)
values (?,?,?,?,?,?)

Question:- Why SSIS is unable to assign values in the 1st sql,  but it is assigning the values to 2nd sql?
We have to ttunate load all 50 tables if the its month end else we have to truncate and load only specific tables.

Appreciate all your help!!

Thanks in Advance!!