edit other windows application elements like textbox

Can you please point me into the right direction.

i wanna edit other application textbox or click with programing. for example like web i can edit elements and invoke button click ?

i have no idea how to do this, but i can move mouse and use keyboard run time is it possible to edit other application textbox ?

i have c++, vb.net, and c# knowledge any suggestion or sample code ?

thanks.