The question asked was how to get the VMA coefficients from the VAR
specification. The answer is from a Hasbrouck 1992 paper on the TORQ
data. The comment is on page 39 in the middle of the page.
Specifically:
To get the vector moving average (VMA) form of the model, it is
necessary to result to a little trickery. Strictly speaking, SAS does
not invert a VAR. It can compute forecasts, however, and this ability
can be used to construct the VMA. The VMA coefficients may be
computed from the forecasts subsequent to unit shocks on the
variables.
In other words use the impulse response option on the model
statement. This will generate an output of the VMA coefficients.