Below IE9, Internet Explorer has effectively zero inbuilt support for CSS3 or any other standard web technologies such as SVG that would allow you to rotate text cross platform as you wish. Microsoft have included two ways of rotating elements (eg text) since IE6, however the more simple method only works in increments on 90 degrees, like so:
-ms-filter: "progid:DXImageTransform.Microsoft.BasicImage(rotation=3)"; /* 0=0, 1=90, 2=180, 3=270 */
If you really need to attain that 340/-20 degrees you included in your example then you will need to try your hand at something more difficult, documented here: MSDN Matrix Filter. Given how unnecessarily complex that looks, a quick Google search revealed a nice calculator that will generate an
-ms-filter CSS rule for you: Matrix Calculator.
Bear in mind that both of these features are meant to be deprecated in IE9 which I believe supports
-ms-transform instead. Depending on whether Microsoft defines deprecated as removed or advised against you may want to check that IE9 isn’t rotating your text twice.
-ms-filter: "progid:DXImageTransform.Microsoft.Matrix(M11=0.93969262, M12=0.34202014, M21=-0.34202014, M22=0.93969262,sizingMethod='auto expand')"; /* IE6-8 */
-ms-transform: rotate(-20deg); /* IE9+ */
-moz-transform: rotate(-20deg); /* Firefox */
-o-transform: rotate(-20deg); /* Opera */
-webkit-transform: rotate(-20deg); /* Safari & Chrome */
margin: 0 10px 0 0;