Q: I want to add an extended numbers so I only have to click the dial feature for a phone number once?

I use a lot of long  phone numbers for dialing.  I want to know if there is a way to enter a number with an extension number ie 1-800-555-5555 ex 3454

or if I need to per-dail one number to get to the next number 1-800-555-5555 pause 2 seconds 1-888-555-5555

Is there a way of doing this on an iphone? 4s or 5s