How to mask string?

Question

I have a string with value \"1131200001103\".

How can I display it as a string in this format \"11-312-001103\" using Response.Write(value)?

Thanks

Answer 1

Maybe something like

string result = str.SubString(0, 2) + "-" + str.SubString(2, 3) + "-" + str.SubString(7);

str being the "11312000011103" string