You could do it a couple of ways...
1) You can create an ASP.NET page that would take in values and generate a JPG and return it as a result. So your javascript would look something like:
Form1.PictureBox1.value = "http://myserver/myservice.aspx?value1=2&value2=3";
It will automatically then load in the picture of the graph that you created on the server.
2) Is a little bit of a hack... you can use the Label controls and add white space to the values of the controls to set their lengths. Then set the background color of the labels to be different colors... The code would look like this:
Form1.label1.value = "<some-whitespace>";
Form1.label2.value = "<more-whitespace>";
Form1.label3.value = "<less-whitespace>";
I had to put in the <x-whitespace> because the forum page was not showing what I want..
You would probably have to do some fancy math to make it fit on the screen but it would end up looking like the following:
create chart on blackberry 
