Random alphanumeric generator

or

Sub tst()
 Randomize

 c00 = Join([transpose(index(char(row(65:90))&char(row(97:122)) ,))], "") & "0123456789"
 For j = 1 To 6
  c01 = c01 & Mid(c00, Int(Len(c00) * Rnd) + 1, 1)
 Next
 
 msgbox c01
End Sub