Extract and return string from ClientID

Hi there

I am relatively new to asp.net so please excuse my ignorence. Any help is really appreciated.

In my ascx page, I am currently retrieving values using <%= lblid.ClientID %>

The values that get generated are for example ucBox0_ctl01out_lblid, ucBox0_ctl02out_lblid, ucBox0_ctl03out_lblid etc.

What I want is to actually return values like this:

ucBox0_ctl01out_lblid to ucBox0_ctl00
ucBox0_ctl02out_lblid to ucBox0_ctl01
ucBox0_ctl03out_lblid to ucBox0_ctl02
etc...

So the question is how do I extract the data I need and return it in the format I want? 

I was thinking to remove "out_lblid", ...