TO_NUMBER, specify the decimal separator, within a query.

[JuanAlem]

I need to change the decimal separator from (comma) to (point) inside a "SELECT" query

select TO_NUMBER('10,35','999G990D00','nls_numeric_characters=''.,''') amount 
from dual; 

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ORA-01722: invalid number

I do not want to use the sentence "ALTER SESSION". It's possible?