Incremented variables?

Hello,
I was wondering if there a way to check if a variable(x) exist…
Let me try to explain a bit more:
Let’s pretend i load 5 variables from a text file named myvariable1 , myvariable2, … , myvariable5
How can i check if “myvariable(x)” = true where x = 1 or 2 or 3 … as they were incremented…??
Does that make sens? Any ideas?

Thanks =)