Industry-Year regressions - excluding observations - need advice


I am trying to run firm-year specific regressions in SAS to get to an expected value for industry-year. However, I need to exclude the i'th observation. For example, if there are 20 observations for 1995 for a specific industry (IND), the regression for obs 1 would be based on obs 2-20. The regression for obs 2 would be based on obs 1 and obs 3-20. I can't seem to find a way to exclude the variable individually. I found a reweight function that can exclude a specific observation by changing the weight to zero, but I would have to do that for every observation and run thousands of individual regressions. If I didn't need to exclude the i'th observation I know the code would be:

Proc Reg;
by fyear IND;

Any ideas on how to exclude the observation? Thanks for the help.