Custom index that changes components each month

Hi,

I want to track the performance of a custom index though time. The components of the custom index change at the start of next month. How do I string the months together through time?

I’ve tried a few things, but doubt they will work…
Attempt 1: can I use an operator to string Plot1 and plot 2 together?

//Define Month 1 
M1 = MONTHNUM() == 1 and YEARNUM() == 2022 ; 
//Define Index for Month 1 
Plot1 = POWER(XLRE:US * XLP:US * XLB:US * XLK:US ,POWER=0.25) ; 
// Display Plot1 During Month 1 
V1 = VALUEWHEN(M1) == Plot1 ; 

//Define Month 2 
M2 = MONTHNUM() == 2 and YEARNUM() == 2022 ; 
//Define Index for Month 2 
Plot2 = POWER(XLF:US * XLY:US * XLB:US * XLK:US ,POWER=0.25) ; 
// Display Plot2 During Month 2 
V2 = VALUEWHEN(M2) == Plot2 ; 

//String the Plots Together through time?????? How???
Plot1, Plot2

Attempt 2: will some type of If statement work?

//Define Month 1 
M1 = MONTHNUM() == 1 and YEARNUM() == 2022 ; 
// Define Month 1 Custom Index 
Plot1 = POWER(XLRE:US * XLP:US * XLB:US * XLK:US ,POWER=0.25) ; 
// Get Data From Custom Index 1 During Month 1 
V1 = VALUEWHEN(M1) == Plot1 ; 

//Define Month 2 
M2 = MONTHNUM() == 2 and YEARNUM() == 2022 ; 
// Define Month 2 Custom Index 
Plot2 = POWER(XLI:US * XLF:US * XLB:US * XLK:US ,POWER=0.25) ; 
// Get Data From Custom Index 2 During Month 2 
V2 = VALUEWHEN(M2) == Plot2 ; 

//Plot Custom Index through time 
If(M1, M2, Plot1, Plot2)

Hopefully you understand what I am trying to do. I thought about the changeto function. What do you recommend? Thank you.

Thanks Louis, but that’s not possible in scripting. All I can think of is to copy the custom index data for the required months to Excel and manually create a continuous dataset which can then be reimported in to Optuma.

Thank you Darren. That is what I will do.