You cannot achieve your objectives in the manner you suggegst, but if you open a joint account then the balance can pass automatically to the survivor. Incidentally you do not need to have your will prepared by a solicitor, although that is best for anything beyond the most straightforward. You can get some instructions on how to write your own will from
http://www.centralwillregistry.com/
Neither does your will need to be witnessed by a solicitor, just two people who are present together when you sign the will, and who are not receiving a gift under the will. If they are a beneficialr then the gift fails.