How can i specify a StationGlobal using text and variables

Hello,

i have two StationGlobals (numeric):

StationGlobals.One

StationGlobals.Two

And there is a FileGlobal.parameter (string) that contains the text "One".

How can i set an expression using something like:

StationGlobals.+FileGlobals.parameter = 12

So the second part of the StationGlobal is defined by another variable.

Thanks