how to select button like filed embeded in div tag in webpage using xpath

Hi,
i have following html source taken from firebug

<div class="parent">
.
.
.
 <div class="nm" role="navigation">
  <div id=":05" class="ac">
   <div class="z0">
    <div class="abc uvw xyz" ……>doTask</div>

there is button like field in my webpage with the labeled with doTask ,i need to Click on this button

->i have tried following but didn't worked, can you please help in solving this

1.selenium.click("//div[contains(text(), 'doTask')]");
2.selenium.click("//div:contains(.,'doTask')");
3.selenium.click("//div[starts-with(@class, 'abc')]");

4.selenium.click("//div[starts-with(@class, 'abc.uvw.xyz')]");


Thanks,
Narender

This is i want to do in Selenium RC

Gentle reminder

i have tried getting this id from Selenium ide,but that also still not working

selenium.click(".//*[@id=':05']/div/div");

Thanks in Advance,
Narender

try this

//div[@class='nm']//div[2]/div[contains(text(),'doTask')]

Thanks for the reply,i have able to do that using below

firebug html source small change in source from earlier i have posted

<div class="nm" role="navigation">
  <div id=":05" class="ac">
   <div class="z0">
     <strong>doTask</strong>

i have used
selenium.click("css=#:05 > div.z0 > strong");

Thanks for the effort. It really helps.