Multiplying Letters and Numbers

Hi everyone, first time posting. Kind of a newbie at excel here, and I've gone through most of the forum and some of the internet in a search for this answer, and I apologize if it's been answered before, but I couldn't find it.

I'm trying to multiply a column of letters by a column of numbers and have the resulting sum product appear in one cell.

I'd like to keep the formating of the text and only have numbers greater than 0 contribute to the multiplication (showing up in the answer). The problem I'm working on is related to chemical reactions, and I've attached an example sheet.

I can't say I really know how to work with VBA, so a formula solution would be fantastic if there is a way to do it without VBA.

Any help would be incredibly appreciated! Thank you for your time.

Best.