To explain the background for Rush's answer,
export does not do anything with the executables in
export PATH simply means "I want the PATH variable to be inherited by all child processes." And what happens when you type
myprogram on a prompt and press Enter is a series of lookups within the shell.
When a command is specified in BASH without a pathname (e.g. myprogram, or ls), and it isn't an alias, function, builtin or keyword, BASH searches through the directories in PATH, in order from left to right, to see whether they contain an executable of the name you typed.
$PATH, in other words, is a list of directories, which is why it can't be used for single commands (except implicitly, by putting the executable in a separate directory). You can't promote a command to a builtin or keyword, but you can create a function or alias. See the previous link for a simple explanation of their differences.