Specifying flat rate shipping for a specific coupon code

[upkansas]

I am trying to set up flat rate shipping for an upcoming promotion we are running on specific products. I have set up a tiered coupon code that applies discounts when the customer has one of these sale products in their cart, and that is all working fine. However, I have created a shipping rule to charge a flat rate to anyone who uses the coupon code for this sale. I have the shipping rule set to "Replace" the default shipping rates with a flat rate, but that flat rate never shows up as an option in the checkout. If I just enable flat rate shipping in the Shipping Methods Config, then it shows up for every order, which is not what I want. I only want flat rate shipping for customers who use this specific coupon code. Any idea what I'm doing wrong? It is very easy to specify free shipping for a coupon code, but I can't seem to get this flat rate option to work. Thanks.

[upkansas]

Some more details for clarification:

I am not using an extension; I'm just trying to accomplish this in Magento 1.9.4.2.

I am not attempting a shipping rate reduction, but rather a flat shipping rate for each order. Everyone who enters the coupon code should pay $3.50 for shipping. If they don't enter the coupon code, then they should pay our normal shipping table rates.

I have set up a Shipping Rule as follows:

Status: Active; Shipping Carriers: Flat Rate; Shipping Methods: Flat Rate; Coupon Code: [entered]; Days of the week: [all selected]; Priority: 0; Calculation: Replace; Base Rate for the Order: 3.50; all stores and customer groups selected.

Shouldn't a shipping rule with these settings replace the default shipping rate with a flat rate of $3.50?

I work at a university where I manage one ecommerce website. I do not administer the Magento platform for the entire university, and I am not a programmer. 

[davidlynnd0568]

Did you ever find a solution for this? I need to do the same?

[calcurates]

@davidlynnd0568 @upkansas not sure this could be done for the Flat Rate as Cart Price Rules in default Magento is pretty bounded. Our solution includes the Shipping Rules feature which is flexible enough. You will be able to configure the rule with a coupon code as a condition.