Building Code Dynamically

I am designing animation that takes cues from an array. The array is created from a text file. The array looks like this:

[man._x=,20,30,40,50,60]

Notice that in the zero position I have a reference to _x for the xpos of the item "man._x". I want to concatenate the man._x AND each of the numbers sequentially.

I cannot figure out how to concatenate the "._x" part. Eval does not work for me. A simpler way to describe the problem is in the following question: "How do I create a complete object/property call from a string and have it execute?"