Selenium Regular Expression

Selenium supports a few methods that help match text patterns. However, selenium locators don’t accept regular expressions. Only patterns or values accept them.
Globbing:

selenium.click("link=glob:*Gifts"); // Clicks on any link with text suffixed with 'Gifts'
selenium.verifyTextPresent("glob:*Gifts*");

Regular Expressions:[regexp, regexpi]

selenium.click("link=regexpi:^Over \\$[0-9]+$");  //matches links such as 'Over $75', 'Over $85' etc

Contains:

selenium.highlight("//div[contains(@class,'cnn_sectbin')]");  //highlights the first div with class attribute that contains 'cnn_sectbin'
selenium.highlight("css=div#cat_description:contains(\"to last\")");  //locating a div containing the text 'to last' using css selector

Starts-with:

selenium.click("//img[starts-with(@id,'cat_prod_image')]");  //clicks on the first image that has an id attribute that starts with 'cat_prod_image'
selenium.click("//div[starts-with(@id,'tab_dropdown')]/a[last()]");  //clicks on the last link within the div that has a class attribute starting with 'tab_dropdown'
selenium.click("//div[starts-with(@id,'tab_dropdown')]/a[position()=2]"); //clicks on the second link within the div that has a class attribute starting with 'tab_dropdown'
selenium.highlight("css=div[class^='samples']"); //highlights div with class that starts with 'samples'

Ends-with:

selenium.highlight("css=div[class$='fabrics']"); //highlights div with class that ends with 'fabrics'
selenium.click("//img[ends-with(@id,'cat_prod_image')]"); //clicks on the first image that has an id attribute that ends with 'cat_prod_image'

[Note: ends-with is supported only by Xpath 2.0. FF 3 might throw an error for this.]
Ref: http://blog.browsermob.com/2011/02/regular-expressions-and-pattern-matching-with-browsermob-and-selenium/