I created a matrix named "m" with the following commands.

Is there a simple way to remove all the rows and columns starting with "/:" or ending with ":_cons"?

Code:
webuse auto.dta, clear
gen int1 = headroom * mpg
sem(weight <- headroom mpg int1)(price <- weight headroom mpg int1)
mat m = e(V)
mat list m

---

symmetric m[11,11]
                        weight:        weight:        weight:        weight:         price:         price:         price:         price:         price:             /:             /:
                      headroom            mpg           int1          _cons         weight       headroom            mpg           int1          _cons  var(e.weight)   var(e.price)
weight:headroom      102070.61
     weight:mpg      13858.559      1981.9523
    weight:int1     -4794.1639     -666.58196      234.94889
   weight:_cons      -304632.4      -42530.83      14038.399      953243.42
   price:weight      3.743e-12      4.958e-13     -1.746e-13     -1.099e-11      .42736644
 price:headroom     -2.781e-08     -3.508e-09      1.189e-09      8.446e-08      -307.2345      3448866.5
      price:mpg     -3.368e-09     -4.182e-10      1.419e-10      1.022e-08       9.181739      431677.77      62876.738
     price:int1      1.300e-09      1.635e-10     -5.738e-11     -3.826e-09      11.587202     -159946.05     -20831.787      7744.4502
    price:_cons      6.341e-08      7.809e-09     -2.510e-09     -2.009e-07      -1281.844     -8712515.3     -1372582.2      409211.32       33991200
/:var(e.weight)      5.831e-08      8.129e-09     -1.916e-09     -2.316e-07     -2.021e-11      1.376e-08     -3.658e-10     -5.317e-10      6.045e-08      9.132e+08
 /:var(e.price)      6.178e-08      5.466e-09     -4.305e-09     -3.546e-08     -3.278e-10      7.628e-06      9.238e-07     -4.163e-07     -.00001609     -1.347e-06      9.133e+11