c:\test>perl -e"printf qq[Line %010d\n], $_ for 1 .. 25" > junk.dat

c:\test>type junk.dat
Line 0000000001
Line 0000000002
Line 0000000003
Line 0000000004
Line 0000000005
Line 0000000006
Line 0000000007
Line 0000000008
Line 0000000009
Line 0000000010
Line 0000000011
Line 0000000012
Line 0000000013
Line 0000000014
Line 0000000015
Line 0000000016
Line 0000000017
Line 0000000018
Line 0000000019
Line 0000000020
Line 0000000021
Line 0000000022
Line 0000000023
Line 0000000024
Line 0000000025