Lookup and values from Web Service

Hi Everybody,

is it possible to override the search function in a lookup in the following way:

- when the user starts typing in a lookup field, BPM Online contacts an external web service which will send back some records according to the current text in the lookup field

- the lookup will then offer these records for selection

- after selection, the record will be saved into the database

Is it possible? If so, can you give me some hints?

Thank you!

Petr