Does anyone know if this is possible?

I have a multisheet workbook that I am trying to copy formulas with having to keep manually referencing a certain sheet.

On sheet named "data", I have a formula that is written B4=Jan!B12. It is just equals what ever I input into cell b12 on the January sheet. I need to paste this formula on the same "data" sheet but in cell B39. However I also need it to increase by the next cell down in sheet January. So it should look like this B39=Jan!B13.

I hope I explained this ok...

Thanks for the help!