Add ZERO(0) before any number in Excel

I am facing problems with adding zero(0) before bank account no. in the Requisition of excel. I clarify my problem . Let say my bank account no is 01234567891234. So for the bank account 0 is essential but when I put the zero before any no excel automatically discard the zero when in number mode up to zero decimal as zero before a no has no significance. So I have to manage the zero with one space 0 1234567891234 but that is not the right account no. So my request is if anybody help me in this regard.