ah i see, thats fair enough, to be honest i do infact want a tab before the first message of the readings to i've added it. i've done some jiggery pokery and using your flow to simulate it i've managed to get the values out as numbers with board names as CSV headers
for your curiosity this is how i jigged yours:
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4,","skip":"0","strings":true,"include_empty_strings":true,"include_null_values":true,"x":590,"y":640,"wires":[["be18bb8c452ef282","b17e46e1c13e1ab3"]]},{"id":"be18bb8c452ef282","type":"file","z":"7bfc1276c35b6509","name":"","filename":"C:\\Users\\223131446\\documents\\CSV.xls","filenameType":"str","appendNewline":false,"createDir":true,"overwriteFile":"false","encoding":"none","x":910,"y":640,"wires":[[]]},{"id":"368c0794da18eb4c","type":"inject","z":"7bfc1276c35b6509","name":"On Start Up","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":true,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":130,"y":100,"wires":[["2afa3d1da87c5f3a"]]},{"id":"736f27152da7eb26","type":"link in","z":"7bfc1276c35b6509","name":"link in 1","links":["c847e5c58cde0c9b"],"x":65,"y":640,"wires":[["49412ebf550e8a93"]]},{"id":"fcab9a3611ea143b","type":"link out","z":"7bfc1276c35b6509","name":"link out 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File Header","func":"msg.payload = '2kV Test Readings' + '\\n'\nreturn msg","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":440,"y":100,"wires":[["fcab9a3611ea143b","be18bb8c452ef282"]]},{"id":"06effc064c18e04b","type":"function","z":"7bfc1276c35b6509","name":"Pad Column","func":"msg.payload = '\t' + msg.payload\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":610,"y":360,"wires":[["c847e5c58cde0c9b"]]},{"id":"49412ebf550e8a93","type":"function","z":"7bfc1276c35b6509","name":"Split to Columns","func":"msg.payload = msg.payload.split('\t')\nreturn msg","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":270,"y":640,"wires":[["bf3167a5aa971165"]]},{"id":"b3d3c7247052f86b","type":"switch","z":"7bfc1276c35b6509","name":"Started?","property":"started","propertyType":"flow","rules":[{"t":"true"}],"checkall":"true","repair":false,"outputs":1,"x":440,"y":360,"wires":[["06effc064c18e04b"]]},{"id":"b17e46e1c13e1ab3","type":"debug","z":"7bfc1276c35b6509","name":"debug 6","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1060,"y":520,"wires":[]}]
and it's allowed me to present the data in excel like this: which is near spot on!!!
with that i should be able to integrate it to the full flow that is taking the serial data 
thanks again for your invaluable help marcus
