if condition depending on url or address

[Super Jinni]

Hi everyone,
I'm wondering if there is anyway to set an if condition depending on page url or address and on the last part of url, like:

when user go to usercp and go to edit his signature I want him to get notification on the header or change the header or something like that

the links are usually like this

http://www.xxxxx.com/forum/profile.php?do=buddylist
http://www.xxxxx.com/album.php?u=1
http://www.xxxxx.com/private.php?do=newpm
http://www.xxxxx.com/forumdisplay.php?f=10

so what I want is:
1- set a condition depending on the last part - which is in red- of the link.

2- set a condition depending on the whole link.

is there anyway to do that?
appreciate your help

best wishes