Thanks for both of your replies.

blowtorch - I tried the code you have given, but ended up with the same result --> 123s is a test

I am using Korn Shell which comes with the Microsoft Services for Unix Applications (SUA) add on component to Windows Server 2003 R2.

Is there a command which I can use to insert a string into the other string - either in the middle or at the end? For example, it would count the number of characters in "This is a test" and then append after then 14th character.