Searching each cell for any combination of 3 characters

Hi there,

I'm currently working on a macro that tallies each "A", "G", and "S" that occurs in a column. So, if a cell's contents was "AG", I would like variables atally and gtally to each get +1 to their value. I would also like atally and gtally to each get +1 if the contents are "GA" as well.

I initially only had to work with "G" and "S", and used a "B" to indicate *both G & S*, but the introduction of a new value "A" screws things up big time.

Currently, my relevant portion of the macro is essentially:
(This macro starts by selecting the first cell value of the column and moves down to the next cell right before it loops)

Do until Selection.Value= ""

If selection.value= "G" then
      gtally = gtally + 1
elseif selection.value="S" then
      stally = stally + 1
elseif selection.value="B" then
    gtally = gtally + 1
    stally = stally + 1
end if

Selection.Offset(1, 0).Select

Loop

What I would like it to look like is this:

Do until Selection.Value= ""
   
If the cell contains the character "G" then
      gtally = gtally + 1
elseif the cell contains the character "S" then
      stally = stally + 1
elseif the cell contains the character "A" then
      atally = atally + 1
end if

Selection.Offset(1, 0).Select

Loop

How do I do this?