There are many examples of reading data from Excel into LabVIEW. Go to the Devzone and search "excel" to find some of these. (www.ni.com/devzone). Once you get the particular data from Excel use this KB to convert the strings back and forth from ASCII to Hex and Vice Versa.
http://digital.ni.com/public.nsf/websearch/77C8F61D36F5A23086256634005ACB38?OpenDocument
Hope this helps,
Rick Kuhlman