been stuck on this for a while.

For every row, I'm trying to count across the columns for all values greater than 0. But the caveat is that I need to specify the starting column to start counting across using each row's specific value in another column.

For example the table would look like this:

```
ID      |     StartWeek     |     1     |     2     |     3     |
123             2                 3           0           1
456             1                 1           0           1

```

Expected output would look like this:

```
ID      |     StartWeek     |     1     |     2     |     3     |   CountRow   |
123             2                 3           0           1           1
456             1                 1           0           1           2

```

I tried something like this:

```
df <- df %>%
mutate(CountRow = rowSums(.[StartWeek:5] > 0))

```

But it just gives me the entire column instead of the individual value of each row. I think I read upon a potential solution using groupby() but would there by another way of doing this just by accessing every rows certain value instead of calling the entire column.