Convert formatting from time to number

I export stock from our POS system into a CSV. Each row is a stock item. It lists into one column the following example 1:1 3:2 4:1 which basically means store one has one item, store 3 has 2 items, etc. I move them out by using text to columns and then cut and paste into a column per store. I know very tedious. Anyway when I want to remove the store prefix (ie 1 to only show the quantity excel keeps formatting as time, which then creates other issues.
I just need a column heading of store number then the quantity listed below
I tried replace, changing formatting and I converted to .xlxs with no luck
Thanks