[Eqtn,Eqtn,...] = findeqtn(M,Label,Label,...)
[List,List,...] = findeqtn(M,'-rexp',Rexp,Rexp,...)
M [ model ] - Model object in which the equations will be searched for.
Label [ char ] - Equation label that will be searched for.
Rexp [ char ] - Regular expressions that will be matched against equation labels.
Eqtn [ char ] - First equation found with the label Label.
List [ cellstr ] - List of equations whose labels match the regular expression Rexp.