Estimate at completion (EAC)

I have a spreadsheet that I need to find the Eac for. I am able to come up with the formula horizontal across columns but not able to figure out the formula vertically down rows.

For example
Jan Feb mar apr etc. (I was able to calculate the eac)

Jan
Feb
Mar
Apr
Etc. Not able to figure out the formula that will allow me to capture the Eac with out having to manually do this each month.