Expense Report Module

We are looking for a custom solution to employees submitting expense reports. We are currently running Drupal for our intranet. Below you'll find a basic functional spec. Could anyone let me know if they've implemented such a module or integrated Drupal with another such module.

Expense Report Project Spec
We need to develop an electronic process for submitting and tracking expense reports. This isn’t so different from any business expense reports software through third party applications or online. If Drupal isn’t the best platform for this, these other applications will likely be considered.

Form
The form would have areas for mileage/parking, cell phone and miscellaneous expenses. We already have a number of user profile data that is updated weekly and that can be pulled into the form.

Workflow/Actions
The form needs to have a workflow which routes to staff’s supervisors for approval and eventually to Accounting. The supervisor information is included in the profile information we import. It’s possible it would also need to be sent back to the staff person for editing. Appropriate e-mails would need to go to relevant parties when the form goes through each step.

Tracking
The form would need to be tracked by the staff, supervisor and Accounting. There would need to be displays of processed forms, in-process forms and waiting for approval forms.

Access Control
The form and tracking would need some levels of access control, so only staff, supervisor and Accounting could see relevant forms.

Export
The final approved forms would need to be exported in some Excel, CSV format for Accounting.

It doesn’t look like an existing Drupal module can handle all of these functions! It might be possible to get this functionality out of the combination of modules like, CCK, Workflow, Actions, Views, but would it be stretching Drupal?