Dynamic Summation with VBA

Okay, I have a problem that's most likely relatively simple, Its just that I haven't used VBA on excel a great deal. I have a column lets call it C, which is used to record numbers. However the amount of rows is dynamic, it increases. There are also gaps between entries, so there will be some empty rows between numbers. Also I want to output the sum at the bottom of this dynamic list. If it helps lets say there is the string "Sum" in column A, so position Ax, (x is a number) next to where I want the result to be. I was thinking we could use that to find where to put the sum, Cx, and the sum just ranges from above this location to say the cell C8.

Thanks for any assistance.