I have searched the forum and was unable to find the answer to my question. Granted, the title of my post was not easy to write clearly/succinctly.

I would like to test for differences in multiple sets of coefficients in a regression. I know how to do this. Here is an example and code:

Code:
sysuse auto, clear
reg price weight length displacement mpg
test weight length
outreg2 using T1.doc, tstat bracket label  addstat(P-Value (Weight=Length), `r(p)') replace
reg price weight length displacement mpg
test weight mpg
outreg2 using T1.doc, tstat bracket label  addstat(P-Value (Weight=MPG), `r(p)')
Both regressions are the same. The "addstat" from the first run of the regression tests and outputs whether or not the weight coefficient is significantly different from the length coefficient. The "addstat" from the second run of the regression tests and outputs whether or not the weight coefficient is significantly different from the mpg coefficient.

What I would like to do (and don't know how to do) it to combine the "addstat" tests for differences in coefficients into the same/first column. I would like the second to last row of the first (and only) column to be P-Value (Weight=Length) and the last row of the first (and only) column to be P-Value (Weight=MPG).

Any help is greatly appreciated. Thanks in advance.