Visio Guy

Hey Everyone,
I started automating some Visio tasks that are done a lot here at work. One of the things I wanted to do was import a range of data from an Excel sheet, and turn that data into shape data.
I got that figured out, but now I need to take certain parts of that shape data and turn it into visible data graphics on its shape. With the number of times this needs to happen, using the UI to do it is unreasonable.

Ultimately, I want to have text boxes (call outs?) that can be moved around the shape to label input/output ports. The reason I want to make them data graphics is because I want to be able to change either the call out, or the shape data, and have them update each other.

I already have it drawing rectangles, populating them with the required text, and placing them on the sheet. The problem is that the text doesn't update when I change the shape data.

Can someone help me out with this?

Thanks!