Qlikview will remeber the first value, so if qlikview find 62 and then 0062 "he" think that 0062 will be 62. But if "he" find 0062 first, this will be keept as 0062. All numbers With leading 00 should be format as text to be sure that the leading part stays. I'm pretty sure that somewhere in Your Field WORK_ID have the number 62.
You can do as stalwar1 suggest, but I'll think you have to format it as text after that.
text(num(WORK_ID,'0000') as WORK_ID