How to concatenate a "name.target" with string?

Hello, how are you?

I have this issue:

I have a function -let's call this function "dad", that receives a parameter -let's call it "parameter". Inside dad function, I need to concatenate parameter with a string, to call a function outside function dad. Example:

function dad (parameter) {

parameter.target.onPress = trace (parameter.target  + "_animation") --> this returns "_level0.button1_animation" which is the same as "button1_animation" right?

but when i use it to call a function outside it doesnt work:

parameter.target.onPress = parameter.target + "_animation" ; --> doesn't work.

parameter.target.onPress = [parameter.target + "_animation"] ; --> doesn't work.

but this does work:

parameter.target.onPress = button1_animation

}

function button1_animation {

here i have a tween

}

All i wanna do, is concatenate parameter.target with a string, to call a function outside! is it possible ?

thanks in advance