The reason you are getting the numbers inserted without the comma is because you have specified that the column type is numeric.
If you store the comma in with the number you will need to have the column set as a varchar type.
In the database all of these values should be purely numeric, this means you will not be able to store the comma in the number. It is best to have the numbers unformatted in the db, then just format the numbers server side when you want to display them.
Doing a little looking on the web I found this link that has a formatting function, the Standard format looks like the one you are going for.