How can I change file associations in PortableApps/LibreOffice, specifically with hyperlinks in Calc file?

For example, my WinXP machine is set to open TIFs with Microsoft Office Picture Manager, and the hyperlink in LibreOffice calc file opens TIFs with Windows Picture and Fax Viewer. Why does PortableApps/LibreOffice use a different program than the one associated in Windows?

My machine is running Windows XP Pro x64 edition version 2003 service pack 2
My LibreOffice is running from my application off my portable hard drive that I take to work:
Build ID: 63150712c6d317d27ce2db16eb94c2f3d7b699f
I am using Calc, with hyperlinks in the cells to open network picture files/pdfs/cad dwgs. Pdfs open with acrobat, which they are supposed to do, and cad dwgs open with autocad, which they are supposed to do. Tifs are not opening with the program I’d like them to. Since it’s a work machine, I am not an administrator, so I can’t even change the program TIF/TIFF files are associated with, but I’d still prefer to use Office Picture Manager over Windows Picture and Fax Viewer.