Insert 0 at beginning of field depending on no of characters

Hi
Example below of the data I have. I need to convert dates into DD.MM.YY (8 chars) for SAP. I receive spreadsheets where the date is dd/mm/yy and I use the replace to convert the "/" to ".", then format this column as TEXT. My problem is some of these sheets have hundreds of records and rather than individually scroll through and look for data that requires the "0", is there a way to insert this. I can custom format that it looks as it has the zero, but it is not in the true data.

1.10.12 data should be 01.10.12
11.10.12 this is correct
3.11.12 data should be 03.11.12
3.06.12 data should be 03.06.12 etc

Thanking you
Regards

A