I recently had this question too. Here is the answer I found (was FRC code that I converted to VEX with the help from the Intelitek guy, Adam). (Was programmed in EasyC Pro)
int arm_joystick;
unsigned char arm_output;
while ( 1 )
{
arm_joystick = GetRxInput ( 2 , 2 ) ; // RxInput block
arm_output = ((( arm_joystick - 127) / 4) + 127 ) ; // User Code
SetPWM ( 4 , arm_output ) ; // SetPWM (motor) Block
}
Hope that helps. You can tweak the User Code block so thaat the motor runs at any different speed.