Insert character at a specific position in a string

[torvyle]

Hello,

Let's say I have a string variable with the value "ABCD". How do I insert a 'K' between first and second characters so that the output is: AKBCD?

I tried the following but it's not working:

substr(string,1,0) = 'K';

Thank you in advance.  

[Astounding · Accepted solution]

First step:  make sure your variable has a length of $5 or longer.  Otherwise you need to assign the new string to a new variable.

data want;

set have;

var = cat( substr(var, 1, 1), 'K', substr(var, 2) );

run;