How to copy field to another

hi all,

I have a field as follows:

FieldNAME:     Source                                                       | Modified By       | Modified Date
DataType:        (Code50)                                                   | (Code(20)         | DateTime
Sample1 :        dynmicsusr21 19/01/12 09.01 33PM  |                             |
Sample2:         dynmicsusr2119/01/12 05:02 55AM   |                              |

Expected          dynmicsusr21 19/01/12 09.01 33PM  | dynmicsusr21  | 19/01/12 09.01 33PM
result                dynmicsusr2119/01/12 05:02 55AM   | dynmicsusr21   | 19/01/12 05:02 55AM

How to achieve it ? Note that Sample1 is with space between UserID and DateTime, Sample2 is with NO space.

The good news is that both belong to same user id.