I don't understand why using == doesn't suffice. It does exactly what you said you need, with the extra inherent work on your part.
That said,
0*
will match 0 or more zeros. Likewise,
0{0,5}
will match between 0 and 5 zeros.
That said,
0*
will match 0 or more zeros. Likewise,
0{0,5}
will match between 0 and 5 zeros.