How to Use Regular Expression for IP Address

[kamakhi.panda]

Hi All,
How to Use Regular Expression for IP Address..I want to check the Address in the range 0-255.
so i used the Regex like (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)

But i am getting confuse where i have to apply this Regex.

For Ex i have one Filed GateWay..its a Text Box
so properties are type,name,html tag,Value,Default Value...

Code:

Browser("xyz").page("xyz").WebEdit("gateway").set "192.168.1.25"

So in above script i want to use Regex..

so please tell me the flow where i have to put Regex...i mean on which property and how to put??