Conditional IF statements for merging multiple datasets

I am trying to join two datasets (csv format) by using conditional if statements. First dataset is accident information which does have a unique id (caseno) and the second dataset is roadway information which does not have a unique id. To join the accident file to the road file, I have to match multiple columns, if county in dataset 1 equals county in dataset 2 then we match county route (cnty_rte) in dataset 1 to dataset 2. If they are equal, then we match milespost in dataset 1 to a range in dataset 2, beginning of milepost (begmp) to end of milempst (endmp). So, if the milepost falls in this range, the accident would be a perfect match to the road location. My end goal is to have an additional column in dataset 1 which would denote the unique id (caseno) or if there is no match then '0'.

Here is the link to the file

This is the statement which is not working for me

=IF([@county]=nc11acc[@county],IF([@cntyrte]=nc11acc[@[cnty_rte]],IF(nc11acc[@milepost]>=[@begmp],IF(nc11acc[@milepost]<[@endmp],[@OID],0))))