How do you insert ascending numbers and letters in table cells?

Tried playing around with this from another direction. I needed the first row across the top of my chart lettered (A, B, C, D, etc) and the last column down numbered (1, 2, 3, etc.). But I only needed numering and lettering in certain cells.

I created 4 paragraph styles in InDesign:

1. chart number blue (numbering set to "continue from previous")

2. chart number blue 2 (numbering set to "start at 1")

3. chart letter blue (numbering set to "start at 1")

4. chart letter blue 2 (numbering set to "continue from previous")

I used javascript to add a row and column, then assigned the "continue from previous" paragraph styles to the row and column. Then I inserted a "non-space" figure (end-nested style) that triggers the paragraph styles numbering to appear . (It doesn't show up  once I paste it here, but in javascript the code for end nested style is a red highlighted "ETX".) Then I assigned a different paragraph style to the cells  which did not need a number/letter. And lastly, I assigned the paragraph styles that "start at 1" in the appropriate cells so the numbering and lettering would start again, no matter how many tables preceeded. Got the idea from the following article and adjusted as needed: http://indesignsecrets.com/how-to-number-your-rows-in-a-table.php.

table = app.selection[0];

if (table.hasOwnProperty("baseline")) table = table.parent;

if (table instanceof Cell) table = table.parent;

if (table instanceof Column) table = table.parent;

if (table instanceof Row) table = table.parent;

if (table instanceof Table)

// Add row to top [0]

myRow = table.rows[0];

for (a=0; a<1; a++){

     table.rows.add(LocationOptions.BEFORE, myRow);

     // Need to re-resolve myRow!

     myRow.getElements();

}

// Add column to end [-1]

myColumn = table.columns[-1];

for (a=0; a < 1; a++)

{

    table.columns.add(LocationOptions.AFTER, myColumn);

}

// Apply chart NUMBER paragraph styles to last column

{

            table.columns[-1].cells.everyItem().texts.everyItem().appliedParagraphStyle = "chart number blue";

}

{

            table.columns[-1].cells.everyItem().insertionPoints[0].contents =  ("  ");

}

{

            table.columns[-1].cells[0].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.columns[-1].cells[1].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.columns[-1].cells[2].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.columns[-1].cells[3].texts.everyItem().appliedParagraphStyle = "chart number blue 2";

}

// Apply chart LETTER paragraph styles to first row

{

            table.rows[0].cells.everyItem().texts.everyItem().appliedParagraphStyle = "chart letter blue 2";

}

{

            table.rows[0].cells.everyItem().insertionPoints[0].contents =  (" ");

}

{

            table.rows[0].cells[0].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.rows[0].cells[1].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.rows[0].cells[-1].texts.everyItem().appliedParagraphStyle = "chart text";

}

{

            table.rows[0].cells[2].texts.everyItem().appliedParagraphStyle = "chart letter blue";

}