You could sort the array, and then do a binary search for 04_02_26AA0000 (lowest possible according to ASCII table) and 04_02_26zz9999 (highest possible according to ASCII table) which should represent the lower and upper regions of the array sub-set containing these numbers.
You may need to do a bit of fiddling to test either side of the returned index values to make sure you have the correct index but this should work I reckon.
Regards
Shane.
Using LV 6.1 and 8.2.1 on W2k (SP4) and WXP (SP2)