Rounding values in SDTE (Detail Text) Syntax?

Hello, I am displaying ANGL attribute for elbows in SDTE, like

( STR ( REAL(ATTRIB ANGL) ) )

However I would like to round this value, something like

( STR ( ROUND(REAL ( ATTRIB ANGL ) )) ) or ( STR ( ROUND(REAL ( ATTRIB ANGL , 2) )) )

but the above code doesn't work (it gets literally printed out). 

Any help would be appreciated!