You have to first know your local state case number, which I got from my employer corresponding to that, you can find the regional case number from this spread sheet.
If nothing, from this spread sheet just do a search by your company name and you should hit atleast one match, from that row, get your employer phone number. Thats the phone number, your employer gave DOL.
You can use AVM to find out all the cases from that phone number, ofcourse you can't tell which one is yours but if your date is close and if all the cases have a decision (certified/RFE) on it, then you know they worked on your case too.
OR from this spread sheet look at all cases filed by your employer and looking at the salary and DOT code you can guess which one may be yours.
In short, there is no hard and fast rule unless you know your local case number.
Good luck.