I couldn't find a way to put it at the beginning
Using regex
[Xx][Ii][Aa][Nn][Oo]
How about:
^1[Xx][Ii][Aa][Nn][Oo]
Sadly the program appears to ignore ^
I had tried:
^[Xx][Ii][Aa][Nn][Oo]
and I've just tried your suggestion (shortened to ^1[Xx][Ii])
and it output:
1LztLGfb5dWntB
1XinGyET94coN4Zds3Fx