Looping With ActiveCell

I am working on a sub that will populate a cell based on the values of two other cells.

The ws is of variable length, the columns are A through I. I have the logic done, now I need help with the looping. It only loops through the first row. I believe that my problem is something to do with declaring the ActiveCell and looping with that. Also should I use variable names rather than Range(A2) ex. Dim EMUNCD As Variant
EMUNCD = Range("H2").Value

I have the following code so far

Sub MainMgrRpt()

Dim LstRow As Long
LstRow = Cells(Rows.Count, 1).End(xlUp).Row
For Row_counter = 2 To LstRow

Dim planCase As String
planCase = Range("F2").Value