If I got you right, you are calling a m-file (script) from a pushbutton within a figure.
First of all you should return the Data of the variable you called "V". If you dont use programm.m as a function and you totally dont want to do that, you have to get "V" by loading it into your the workspace of your GUI.
See assignin for example!
now that you have the Data of V, you can use it to display information about it within a listbox like this:
%you have to know the handle of the listbox-> I call it myLB:
%if you want to append data:
myData = get(myLB, String)
set(myLB, String, [myData sprintf('total is %d\n',size(V,1))])
%if you want to replace data:
set(myLB, String, sprintf('total is %d\n',size(V,1)))