Update field2

[Lacutas]

Please can you point me in the right diection. I have a table called DATA, field1 is populated from an import. what I want to do is populate field2 with data. the datain field1 starts with a 4500* and all 100* numbers below relate to the 4500* above it. I need to put the 4500* number at the side of the 100* it relates too. here is an example, I have populated field2 to show you what I mean. Thank you.
Field1 Field2
4501614187 4501614187
10 4501614187
1003499442 4501614187
1003499528 4501614187


1003499529 4501614187
1003499530 4501614187
1003499531 4501614187
4501614187
4501614188 4501614188
10 4501614188
1003499443 4501614188
1003499444 4501614188
1003499445 4501614188
1003499446 4501614188
1003499447 4501614188
4501614188
4501614189 4501614189
10 4501614189
1003499448 4501614189
1003499449 4501614189
1003499450
1003499451

[Lacutas]

Sorted it now, thanks for all your help