I would make sure you have "ttf-mscorefonts" installed on your Kubuntu system. That will give you the core Windows fontson your Kubuntu/Ubuntu system.
Verdana, Tahoma, Georgia, and Trebuchet MS, are core fonts that seem to be apart of most Windows systems. Add those tothe list of others.
So, you are creating a spreadsheet using LO that will be used in Excel? I would stick with the following: Arial, Tahoma, and Georgia.
There is an art and science involved in choosing fonts, or a list of fonts, that wouldbe a good choice to used for documents between systems and OS types. People have even made lists of which fonts are used on one system that would be as close as possible to other font names on other systems.
Personally, I tend to make sure my Windows and Ubuntu systems have the same set of fonts. If I need to share documents that are to be used and edited by others, and I know which OS they are using, I then stick with font names that I know they will have as one of their core fonts.
Since I currently have not installed any fonts on a new laptop, that was not installed by Win7/Home Premium. or LO and any other package, I could make a list of all of the installed fonts in the Win7 laptop and see if I can highlight the ones that were installed by packages like LO and Corel Draw, over top of the ones installed when the OS was placed onto the laptop by Gateway.