Referring to a Column Label When the Label is a Text Expression

Last week, I added an enhancement to a QlikView document that had been in use for over two years. My task was simply to add a column to a straight table that would have an expression like this:  =[column1] - [column2]. It should be pretty simple. 
But the two columns I needed to refer to had text expressions using variables in their column labels. The two column labels looked like this:
=abv_PRICE&' '&lbl_Cmpr&' '&abv_EUAVG
=abv_COST&' '&lbl_Cmpr&' '&abv_EUSTD 

It took a few tries to get the syntax right. I didn't change the existing columns but I copy and pasted their label expressions into my column expression and then modified the syntax and added dollar sign expansion. The expression for my new column still refers to the two other columns using their column labels within square brackets; it looks like this: 
[$(='$(abv_PRICE) $(lbl_Cmpr) $(abv_EUAVG)')]-[$(='$(abv_COST) $(lbl_Cmpr) $(abv_EUSTD)')]

I hope this might help someone with a similar problem to solve. 

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