I'm trying to create a formula which will in the absence of data for itself, reference a column for the first piece of numeric data. However, I'm not sure what formula I should be using. Below is a screenshot and link to create your own iteration of my sheet.
I've highlighted "???" in this formula thinking that perhaps I can solve this with a VLOOKUP formula, but perhaps I'm wrong. As a means to test this out, one of the cells towards the bottom is referencing the "600" value on the left.
I don't know if I'm explaining this well or not, but essentially what I'd like to do is have it so that if a person decides to enter their weight and they don't start on December 26th, the value that shows up for December 26th is the first numeric value they enter for the year.