Please share more info about just how you are "importing" your data, and include some specific SAS log (pasted in your post reply) to more accurately explain the SAS problem you are experiencing. It does not make sense that SAS would read up a data column into a SAS variable and not reference the variable as expected. Do remember though that SAS variable names must start with a character.
Below please find a useful Google advanced search argument against the SAS support http://support.sas.com/ website where you may find relative topic information and product documentation:
I'm importing using the "Import Data" wizard under the "File" menu option. Standard excel file.
The SAS Data table is created and when I view it, I see my field names (column headers) as "F123", F124", etc
When I do a Proc print, the field names are "_F123" etc.
Here is the log:
NOTE: SAS initialization used:
real time 8.70 seconds
cpu time 1.73 seconds
NOTE: PARTIAL.GLT was successfully created.
1 proc print data =partial.glt;
NOTE: There were 1555 observations read from the data set PARTIAL.GLT.
NOTE: PROCEDURE PRINT used (Total process time):
real time 1.09 seconds
cpu time 0.14 seconds