Could you please be more specific with some examples?
What values are provided for the 'UTM Zone' parameter? The name of the coordinate systems? Like this 'WGS 1984 UTM Zone 11N', 'WGS 1984 UTM Zone 12N', 'WGS 1984 UTM Zone 13N' ... ?
And then you want the model to select which UTM coordinate system to use?