How wo control the length of a number field with preceding zero(es)? (FMP6, Win XP2)

Dear Listeners:

I need to create a field for the Dutch "BSN" (citizen service number). It
consists of always 9 digits of which the first (and maybe even the second)
can be a zero (like my own).

If I create a number field, then the number 012345678 is not accepted when I
validate with "BSN either empty or 9 digits long".

I could of course make it a text field and then check for numbers only +
length, or even make 9 different mini-fields ;=(

Is there another way to check the length properly in a number field ? Since
I do not know the minimum and maximum numeric values of the BSN, I can't
check for that, and moreover, that would still not validate for the number
of bytes/digits if the minimum was e.g. 1 (to be presented as 000000001).

BTW, there is a bug in length validating in number fields. I tested the
calculated length:

Value => Calculated length

0 => length 1 (OK)
00 => length 1 (!)
001 => length 1 (!!)
0012 => length 2 (!!)
12 => length 2

TIA

--
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Christoph Bouthillier
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