Question about Outlook Express

My outlook in mac runs on the imap livemail account, but the contacts on the outlook in mac are not uploaded to the virtual livemail account. My contacts are divided in outlook into contact groups and altogether I have over 4000 contacts. I do not want to import all my contacts into livemail, I just want to import one contact group - around 200 contacts. I want these contacts to be visible in livemail and accessible wherever I log into livemail. 

I cannot seem to do this through livemail, I have tried through people > manage > import contacts > import from file , but livemail cannot read any of the files I have tried to upload.

I have tried sending the contacts as a vcf attachment, but I can only then download the vcf files onto my pc, and then open them as vcf files, I cannot seem to be able to take the vcf files and save them into my contacts list.

I have also tried to export a contact group as an oml file (to be able to transfer to a different pc and upload onto a pc and then upload onto livemail from a pc not a mac) but this doesn't work. I cannot do anything with the oml file after I have exported it, I cannot open it, I cannot move it or anything. I need to be able to take the oml and open it on a windows software pc.

So how can I take a contact group from outlook on mac and either open it as a contact group in my livemail account, or transfer it to a windows software pc outlook? 

I'll be grateful for help.