Hi
There are 3 ways of creating search help.
1.Maintain values at domain level of field .If field values are specific .
.2 Go to SE11 and create the elementary search help for the field .
3. As it is custom table ,You may have table maintenance generator . take the function group of table and go to SE80 and in the flow logic use event , 'process on value request' .add module to that field .
use FM 'f4_int_table_value_request'
Thanks
Kamesh