We have found one software suitable in our database for this conversion.
It seems .spo output files from SPSS version 15 or earlier are only supported by this program of the specific version and no other 3rd party viewer or app is capable of exporting the data to anything else.
SPSS supports a broad range of export options including Excel tables or images, however .spo files cannot be opened in latest versions of SPSS.
SPO
Files with spo extension can be found as output documents from SPSS statical and surveying software version 15 or earlier.
XLS
Files with xls extension are best known as spreadsheets from Microsoft Excel. A spreadsheet is basically a grid of cells sorted in rows and columns. Each cell can contain text, numeric or formula data. Excel XLS spreadsheets can be opened in most other similar programs, such as OpenOffice.org Calc.