I want to make a counter system to add to a string, so I have say:
Cell A1 : Bob
but I want to make it into
Cell A1 : Bob1
Cell A2 = Bob2
And so on..

I understand it's along the lines of
Activecell.FormulaR1C1 = *data string 1* + *data string 2*, but how would I use this if data strings 1 and 2 were cell references?

(I know how to do the rest (cell offset etc) but it's just this line I'm struggling with)

Thanks in advance.

This can be done with a simple formula. Type this in the cell then populate down:
="Bob" & ROW()

In code where you're not using a formula:
ActiveCell.Value = "Bob" & ActiveCell.Row

If you are iterating over a range:

Dim CellOn As Range
For Each CellOn In Range("A1:A12")
  CellOn.Value = "Bob" & CellOn.Row
Next