Service Catalog

Service Catalog

We're currently using Service Catalog to request purchases order requests and track them through purchase orders. Is there a way to turn a regular email request into a service catalog request. e.g. 
 User emails they'd like to order a PC it creates a Servicedesk request. This should be a Service catalog request. How can we change this to a catalog request for a purchase

                  New to ADSelfService Plus?