[R] vector operation using regexpr?

[John Christie]

Hi,

Here's my problem... I have a data frame with three columns containing  
strings.  The first columns is a simple character. I want to get the  
index of that character in the second column and use it to extract the  
item from the third column.  I can do this using a scalar method.  But  
I'm not finding a vector method.  An example is below.

col1      col2      col3
'L'         'MAIL '   'PLOY'

What I want to do with the above is find the index of col1 in col2 (4)  
and then use it to extract the character from col3 ('Y').  I could do  
the last part if I could get the index in a vector fashion.

So, the shorter question is, how do I get the index of the letter in  
col1 as it is found in col2?