Sum A Dynamic Range Affected By Macro

Hi All,

I have the following situation in excel 2007:

In Sheet A I have:

Input Quantity
Input1 3
Input2 2
Input3 4

I want to sum the range under quantity, but there is a macro that allows the user to add more inputs, such as (input4, input5,...,inputn). How do I create a formula (or macro) that allows me to sum this dynamic range? I have more data below the inputs above that I do not want included in the sum, but there are blank rows between them. I have seen ways of summing a dynamic range, but they will sum the data below that I do not want included.

Thanks for the help