Get the value of .Contains in C#

Hello guys,

I have one doubt, suppose i have a some string

Say for e.g "Hello world, i am a software developer"

Now I want to check if my string exists in above string then i want to extract that value.

e.g

string mystring= "Hello world, i am a software developer"

if(mystring.Contains("software") || mystring.Contains("abc"))

{

//here if software exists then store the software in below string

string str= //here i want to store the value which i am checking i.e "software" if it exists

}

How do i do this...?

Can anybody tell me...??

Any help would be much appreciated

Thanks !!!