I need to "execute" a formula in a cell.

eg
Sheets("Sheet1").Select
ActiveWorkbook.Names.Add Name:="chr_string",
RefersToR1C1:="=Sheet1!R1C1" ' create a range name known as chr_string
ActiveCell.FormulaR1C1 = "'=chr(65)&chr(66)" 'put chr(65)&chr(66)
into range name
MsgBox (Range("chr_string"))

What is msgbox displayed is "=chr(65)&chr(66)".
I need the msgbox to display "AB" instead (chr(65)="A", chr(66)="B").

Changing the
ActiveCell.FormulaR1C1 = "'=chr(65)&chr(66)"
to
ActiveCell.FormulaR1C1 = "AB"
is not an option as I need to put in some non-printable control chars in
there as well (not for display, but for comparison).

How can I do that make the msgbox display "AB" instead of "=chr(65)&chr(66)"?