VS 2008 Accessing Dynamically Created Picturebox?

For school and other reasons, i am making an application in which the user can draw tile based backgrounds, to then turn into long line of code , i think called CSV , which can then be used in programs such as flash, to draw a tile based background. I am currently making a flash game, and dont really like the other tile array making programs out there.

For instance, code such as [1,0,1],[0,1,0],[1,0,1] with the correct code would generate a 3x3 tile background with an X shape.Anyway, at the moment i am currently stuck.I have code up and running which generates a 2 dimensional background out of pictureboxes randomly, however thats as far as i got, i dont know how to access the pictureboxes created.

What i have right now is two variables, gridX and gridY, which determine the amount of tiles placed in a for loop. These variables would be used to determine the size of multidimensional arrays that store the tile data, and determine the map size.i intended each image to be clickable, so that its picture would change from black to white when clicked

When clicked, the tile would switch between two images, to represent two different tiles. at the same time, a value in an array created with the tile, would change from 1 to 0.Then when its time to make the code, i simply use a for loop to spit out the array in the way i want.

I understand that i could perhaps create a class for the pictureboxes, but i dont know how to, since ive never dealt with them, and i dont understand any of the guides and tuts.how to use a class so that i could add and change the properties of multiple dynamically created pictureboxes, but also change the value of an array created with the picturebox, when clicked?

i need all of this to be done however without adding or including any additional libraries or anything to visual basic as it will be graded on school computers.