Saving emails away – maintain date sent

Hi, any thoughts on the following puzzle:

If I transfer emails from Outlook to Desktop and then to a CD, the date shown is the date of download onto CD. Is there any way that the date sent (which appears in the properties of the .eml file) can be maintained -FOLLOWING THE TRANSFER- as an additional field?

Could the answer be to reinsert an email back into Outlook? Have tried to do that but did not succeed.