Regex for non-alphabets and non-numerals

Please provide a solution to write a regular expression as following in C#.NET: I would require a RegEx for Non-Alphabets(a to z;A to Z) and Non-Numerals(0 to 9). Mean to say as reverse way for getting regular expression other than alphabets and otherthan numerals(0 to 9).

Kindly suggest the solution for the same.