powerbuilder convert integer to string

i want to create a function let call it pic9 which will do the following action
 - it will have two integer values as argument (lets call it  numb, size)
 - it will return a string which will have length=size and it will contain numb right justified  and leading zeros in its rest bytes.

for example

numb     size          result
10             5            00010
10             2            10
10             4            0010
10             3            010