An auto-enter calculation can be set to filter out all but the numeric digits or it can filter out all numeric digits and then reformat the data to include the (),- and spaces to produce the format you want in a manner that is identical for all records.
To filter out all non numeric digits you can use either the filter or getAsNumber functions:
GetAsNumber ( self )
Filter ( Self ; 9876543210 )
Yeah, basically what I want to do is get rid of all characters and spaces so just the 10 characters for the phone number show up like "9999999999". I have another field that acts as a mask to format it when reading so it looks like a phone number :)
Then the above examples will work, but you really don't need the second field if you include the calculation in that other field as part of this field's auto-enter calculation.
Filter was the better choice as if a number is entered that uses a period (.) as a seperator, it will be kept if using GetAsNumber. :)