Does making cel references using text (rather than column header letters) require use of row headers?

I'm looking find out if I can, and if so, how, to reference cels by their header column name, but without using row headers. I've read multiple threads on this here (and found very useful information), but for what I'm after, I haven't found the method yet.

My testing so far:

Cel References: √ Use header name as labels

In the Table Menu, both Header Rows and Header Columns are set to "1".

B1 (the header column) is named "MyConstant"

Cels and their values:

B2: 10, B3: 20, B4: 30

(Both the cels with numbers, and the cel I'm tying to build a calculation with are set to "Number", although I don't think that is necessary.)

This works:

SUM(MyConstant)   [It correctly returns 60, but is a sum of all the rows, which is not what I'm after.]

What I want is to build calculations where the cel reference uses the column name ("myConstant") and the row reference number, rather than: "B2". I've tried the following ways (guesswork), but all return "Syntax error" (note: "MyConstant" is auto filled and in a blue highlight oval):

myConstant2

MyConstant,2

MyConstant:'2'

Ultimately, I am after being able to use the header name in place of the column number instead of letter, as I currently do:

B2+B4

SUM(B2:B4)

Use of header rows:

If I create row headers ("January", "February", "March"), things work:

MyConstant January+MyConstant March   [correctly returns "40"]

My table has rows (in column B) starting with a date, and incrementing by one day for each row (e.g., row 3 displays as: Friday 1/25/19, row 4 as "Saturday 1/26/19", etc.). In column A, I have some other data, but only for certain rows.

I tried moving the data column data to column A, and that worked for row header purposes. I tried using 1, 2, 3, etc., as arbitrary, but unique data, for the row headers, but that did not work, even if I forced the format to text.