Hello,

I want to make cell referencing as a variable. For example, if there is
a sequence of cells {i=1,2,3,...}, I want each cell to reference an
arbitrary number previous cells (i.e., cell[i] will reference cell[i-Y]
where Y can be specified in another cell by a user. So when user
changes the value of Y, it will recompute the whole thing based on
different lag size.

Thanks.