Wild card Characters

Hi

I have a requirement in which I have document header text(BKPF-BKTXT) on selection screen.The user can enter wildcard characters also in the search.For e.g if user enters (test) then it should retrieve all the possible records starting with test.The records can be test123,TEST123,Test123,TEst123,TESt123,tEst123..etc.for eg if user enters Test then also it should return all the possible header texts starting with test.

Please advise.

Regards