Read to multiple textbox

[Heinmann]

I want to be able to open a txt file which will contain something like..

123, Cat, 098, Dog
876, Cat, 436, Dog


so two lines and four columns separated by a comma (the comma i dont want shown in program) so I have an open button and four text boxes.

so far..
the open button works brings up a dialog, I can open a file to a text box (using streamreader) but the problem is how would I read the txt file so it puts relevant column to relevant textbox?

also if I just open the txt file in a single texbox how would I edit each column?
for example say I wanted to change every number in the 1st column numerically so instead of

123,
876

it goes

100,
101,

without effecting the rest of the text

cheers

edit

its a windows application in visual c++2010