Error expanding DSL when #-Character is in right-side of dsl-property

Having a line in a DSL like following:
[condition][]Bedingung-19-MKM4 = eval ( $p.getTempVal("#UML-ATZ-1") < $p.getZvUmlStfr() )

Using "Bedingung-19-MKM4" in the LHS of a rule "Regel-151" in an dslr-File I get the following 3 errors:

[12] Unable to expand: Bedingung-19-MKM4
[ERR 103] Line 201:2 no viable alternative at input 'Bedingung' in rule "Regel-151"
Unknown error while parsing. This is a bug. Please contact the Development team.

The problem is the #-Character. If you change the line to
[condition][]Bedingung-19-MKM4 = eval ( $p.getTempVal("UML-ATZ-1") < $p.getZvUmlStfr() )
it works. But that's not what I need.

Hint: maybe this is related to (JBRULES-1960) Syntaxcoloring wrong if DSLR contains a "#"-Character.

But in this case it's more important because it's not an "optical" problem only.

By the way: if I use the value #UML-ATZ-1 as an argument / placeholder it works (thank God, need this often). But using a placeholder is not what I need.