Value of a variable depending on frame number

[videoFred]

Hello everybody,

So I have a variable X in my script. It controls the amount of FredAverage() overlayed on my GamMac() detect clip.

I want his variable to be 34 for the entire clip, except for certain frames/scenes.

For example this variable must be 34 for frames 0-2000.
Then 64 for frames 2000-2400.
Then again 34... and so on.

What do I need for this?
Conditional reader with an external frame numbers list or something similar?

thanks in advance,
Fred.