how to create custom search box will allow up to 60 alphanumericcharacters & User can input a minimum of 1 character and the system will pull back an exact match on the sequence entered.

Hi,

Can anyone please help me in creating the Custom Search box with below mentioned functionality

"The search box will allow up to 60 alphanumeric characters.User can input a minimum of 1 character and the system will pull back an exact match on the sequence entered"