This one works with quite a few games:
0B 42 09 00 01 1F 0C 84"
with
"0B 42 09 00 01 1F 30 E0"
And this one worked with quite a few games for me:
01 E4 03 A0 02 E4 01 A0 03
and replace it with
00 E4 03 A0 00 E4 01 A0 00
I don't have quake 3 so i can't say they work but if it finds one of these there is a chance ofcourse.
I assume u tried pal patcher? if not first try it
Edit: It can be that q3 is a windowsCE PC port as Resident evil VC2 etc. Open the iso and check if it has a 0wince.bin or a ProjectCE.exe or whatever. if this is the case its winCE and ur out of luck.. the only option then is a pal version with a 60hz switch (i think i saw q3 pal has this).