So the way I was thinking about things was incorrect. I think I was trying for something like this:
Code:
=SUM(D5+INDIRECT(ARRAYTOTEXT(FILTER(MID(FORMULATEXT(D5),SEARCH(TEXTSPLIT(TEXTJOIN(",",TRUE,ADDRESS(ROW(E2:I2),COLUMN(E2:I2))),","),FORMULATEXT(D5)),4),NOT(ISERROR(MID(FORMULATEXT(D5),SEARCH(TEXTSPLIT(TEXTJOIN(",",TRUE,ADDRESS(ROW(E2:I2),COLUMN(E2:I2))),","),FORMULATEXT(D5)),4)))))))
But the next column wouldn't be able to determine what the previous value was gonna be. I really didn't think this through logically. It would need to be script something in vba to get the results I really want.