I have a data frame. One of the columns has string values that I want to use as a condition for the name of the other columns. For example, 

```
df <- data.frame(
  cond=c("a","b"),
  aVal=c(1  , 2),
  bVal=c(3  , 4)
)

```

I want to check the name of each column in the df row by row, if the colname does not start with cond then I want to set the value of that column to 0.
The expected output here will be.

```
#    cond aVal bVal
# 1    a    1    0
# 2    b    0    4

```

I am not sure how to do this with R preferably with dplyr.