How do I write a simple division formula in JMP using different values from the same column?

[#1]

Hello, I'm trying to create a simple division formula to subtract my target gene value from the reference gene. In excel I take values from the same column and divide every second number in the row with the previous value. Its very simple in excel but I can't figure out how to do it in JMP. Does anyone know how I may troubleshoot this?
I have tried splitting my column by target and well and write the formula that way but I've been unsuccessful. 

Here is a pseudo data set; I simply want to calculate true concentration by diving Target A or B by Reference for each well.

Well	Target	Concentration
A1	Reference	10
A1	A	100
B1	Reference	50
B1	B	500

[#2]

If it's seriously just

divide every second number in the row with the previous value

then

If( Mod( Row(), 2 ) == 0,
	:Concentration / Lag( :Concentration, 1 )
)

this obviously won't hold up to sorting though.  

[#3]

If you're worried about sorting breaking the formula, reformatting your data like the example below would be a different way to do it.

[#4]

Alternatively, you can try the Normalization GUI:
 from the QuickSelect Toolbar Add-In 

For your case, the settings will be:

There are many more options - just click on  and get a guided tour.