We have cells that are text and 1 2 3 .....110

the problem is now they want them as
001
002
099
100


can can the 1 2 3 98 99 be converted to leading 0's automatically

this wouldn't be too bad but it also has visit no's

so I have

ID VISIT
1_____1
1_____2
1_____3
1_____4
2_____1
..
..
..
99_____3
99_____4

ect


this is becoming a nightmare to me

thanks for any help