If it is about Oracle SQL, substituting '&' with '&&' might solve your problem.
Ah, sorry ... VBA.
However, if it works in Oracle, perhaps there's something similar. For example, if you have
PHP Code:
SELECT ... FROM table_1
WHERE id = &par_id;
SELECT ... FROM table_2
WHERE id = &par_id;
it'll ask you to enter value for 'par_id' twice. But, if you have
PHP Code:
SELECT ... FROM table_1
WHERE id = &&par_id;
SELECT ... FROM table_2
WHERE id = &&par_id;
UNDEFINE par_id;
it'll ask you only once.