You have the idea mostly right.
You mentioned that you have a menu and in two menu options you want RC Control - you could represent each of your menu options as a mode - MODE_MANUAL, MODE_RC_NORMAL, MODE_RC_XXX etc
Then you can have a 'switch case' statement inside loop which does different things depending on the value of gMode -
switch(gMode)
{
case MODE_MANUAL:
// put your manual control code here
break;
case MODE_RC_NORMAL:
// put your manual control code here
break;
case MODE_RC_XXX:
// put your manual control code here
break;
}
If you modes are very different, one way that I have done this in the past is to have the code I want for each mode in a separate function -
switch(gMode)
{
case MODE_MANUAL:
doModeManual();
break;
case MODE_RC_NORMAL:
doModeRCNormal();
break;
case MODE_RC_XXX:
doModeRCXXX();
break;
// etc etc etc
}
This might also help - http://www.arduino.cc/en/Reference/SwitchCase
Duane B