thanks for the response guys. Basically I need a shell script (sh) as a) that's all I know and b) I think that is the only thing available on the box I'll be running this on. Again I have no idea how to install any new languages onto the box.

I've managed to get quite good performance (less than an hour) by:
1) extracting all the information out of the source file and into 'raw' format by using a multiple sed commands. Raw format is something like event_num~channel~startdate~enddate~title~desc
2) Then using usual read file method to read each line and output it in xml file format. I need the read file method to a) convert startdate/enddate into unix time. I can't get this to work in sed itself (i.e. taking a sed variable and passing it to date function). b) lookup the external file for sid,onid,tsid.

I don't have the script handy, otherwise I would post it here. Again, if you have any suggestions on how I could improve my sed statements to do a) and b) above then that would make it even faster