pl sql block error while prepare sql statement

I written following block in unix .sh file. to pass some variable from unix to oracle.  but I am facing the below error. please help.

                sqmt_alter := 'alter table ' || MYTABLE2 || ' drop (' || ID || ')';

                                                *

ERROR at line 29:

ORA-06550: line 29, column 35:

PLS-00357: Table,View Or Sequence reference 'MYTABLE2' not allowed in this

context

ORA-06550: line 29, column 3:

PL/SQL: Statement ignored

ORA-06550: line 31, column 50:

PLS-00357: Table,View Or Sequence reference 'MYTABLE2' not allowed in this

context

ORA-06550: line 31, column 17:

PL/SQL: Statement ignored

 DECLARE

   my_DATA $TABLE_NAME.$COLUMN_NAME%TYPE;

   CURSOR c1 IS SELECT $COLUMN_NAME  from $TABLE_NAME for update of $mig_column;