z search field in standard sap program

Hi,

I would like to ask if Z search field can be created in the standard SAP program.

Basically I need modify the search field used when searching for Business area in creation of asset master data (tr. AS01).

It shows the list of table tgsbt. But I would like to exclude by default some rows of the table and also would like to sort it in different way (by text).

Is that possible, if so, could anyone give me a hint how to do that?

Many thanks,

Honza