Is there a possibility to add the DueBy date to an Incident template or Service Catalog item for the Requester to be filled in?

For example when a new employee enters the company in 2 months and his/her manager already created an incident for the user account creation. This while there is a very strict SLA regarding user account creation and this SLA is not necessary for this specific case.

Off course we could add custom field called 'DueBy date Requester' or something similar and copy over the value to the 'real' 'DueBy date' field to not mess up reporting.

Any ideas or help?

Thanks,

Laris