I have a table in which one column contains a string. I want to replace the first x characters of that column with another string where the first x characters match another string.

I think I should use the LEFT function to test for the left most characters I want and REPLACE function.

What I need to know is how do I do that in a SELECT statement?

for example
MyCol
-----
abctest
testabc
abchere

I need to replace abc only where it is the first 3 characters of the string.

thanks for the help