Help with regex include and exclude

I would like some help with regex.

I'm trying to create an expression that will include certain strings and exclude certain strings.

For example:

I would like to include any URL containing mobility http://www.something.com/mobility/

However I would like to exclude any URL containing store http://www.something.com/store/mobility/

FYI I have many keywords that I'm using to include. Currently I am including like this /mobility|enterprise|products/i however I am not finding it able to exclude links that contain other keywords.

Thank you in advance for any help and insight you can provide.

_t