use Win32::Registry;
$HKCU->SetValues( "foo", REG_SZ, "bar");

$HKCU->Open("AppEvents")->SetValues( "foo", REG_SZ, "something");
#or
#Win32::Registry::SetValues( 'HKEY_CURRENT_USER\AppEvents', 
#    "foo", REG_SZ, "something");

$HKCU->Create("foo");