Example: ajshdjashdjashdlasdlhdlSTARTasdasdsdaasdENDaknsdklansdlknaldknaaklsdn
1) START\w*END
return: STARTasdasdsdaasdEND - will give you words between START and END
2) START\d*END
return: START12121212END - will give you numbers between START and END
3) START\d*_\d*END
return: START1212_1212END - will give you numbers between START and END having _