Can I do a lookup in a field?

Can I do a lookup in a field?

Hi

Is it possible to do a SQL DB lookup of a value?

For example - one of my technicians needs to put it an image ID from another system. What she would like is in the Service Desk template to already display a list of all the image ID numbers, stored in another database.

It would be nice if we could query a DB and have that dataset be part of a lookup list in SD. 

Is there a different way to help her? She just doesnt want to accidntly enter in the wrong or duplicate image number.