Superlab Datafile import as event in EEGLAB

Hello,
I am currently trying and failing to combine superlabs data file events with EEGLAB as an events import as a txt file.
I am using Brainvision recorder files, importing them to EEGLAB, these contain markers from the cedrus stimtraker for each response made on the computer keyboard. What I am trying to do is use the first Stimtracker marker as an synchronisation point for the rest of the events in the experiment from the data file.
I have tried editing the names of the columns, reducing the datafile header rows to just the information that matlab would need to import it and i continuously get the error message “Cannot add new field to event structure”.
I know this is likely to be a niche request but any help would be greatly appreciated. Im not sure what Im doing wrong & EEGLAB support has not got back to me so i thought i would try here!
Thanks,
Annabel

Unfortunately, we have no experience with EEGLAB.