Create a count on a tab in form

I was waiting for someone to say you couldn't do this but alas nobody came forward. Using the IOL technique and something like this will do the job:

$.get(dbidTable, {
  act: "API_GetNumRecords"
}).then(function(xml) {
  var numRecords = $("num_records", xml).text();
  $("#tab_t1_link a").append(' (${numRecords)');
});

Notes:

(1) This is only the essential code. You will have to modify the code for your specific parameters and repeat the code for each child table.

(2) The above code will append to the tag name a string counting the number of child records in parentheses:

Tab 1 (100)  Tab 2 (200) ...

I think I may be looking for the same solution. I have attached a photo of what I am after. Is this code the way to making it happen? I am familiar with Rules and formulas, however coding is far beyond my skill set at this point [I don't even know where to enter codes]. can someone walk me through this?