Automated emails from date subtraction

I designed a Sharepoint site in our organization which tracks when computer software should be renewed.  I designed the site using Sharepoint Designer 2007, and worked my way through learning it on my own so I am new to Sharepoint (and workflows).

Is there a way to have Sharepoint send out automated emails when Current Date is 90 days away from the field of 'OMB Expiration Date'?  Example:  If the expiration date is 10/01/12, have an automated email sent on 07/01/12 (or whatever exactly 90 days is), to "bob.jones@ssi.com, charlie.smith@ssi.com, jeff.golden@ssi.com" saying that

In the OMB Title field in Sharepoint is the name of the software.

Example of a 07/01/12 email:
"The software (OMB Title) will expire on 10/01/12.  Please advise IT if you wish to renew or not renew this sofware.  Thank you."

Please let me know if you have any questions.

Thank you for your help!
James