Information about control data
Without control data from your subjects, I don't think there's really no way to distinguish somatic mutations from germ-line mutations. The best you can do is to screen out common variants, which are germ-line mutations that are shared by large numbers of individuals using the population frequencies from something like the  Exome Aggregation Consortium:

annotate_variation.pl -downdb -webfrom annovar -build hg19 exac03 humandb/
annotate_variation.pl -filter -build hg19 -dbtype exac03 example/ex1.avinput humandb/