Digraphs

Please help me

In Polish digraphs using like letters, but snowball compiler ignoring it

stringdef ia   hex '69 61'
stringdef ia"  hex '69 105'
stringdef ie   hex '69 65'
stringdef ie"  hex '69 119'
stringdef io   hex '69 6F'
stringdef io"  hex '69 F3'
stringdef iu   hex '69 75'

stringdef ch   hex '63 68'
stringdef cz   hex '63 7A'
stringdef dz   hex '64 7A'
stringdef dz"  hex '64 17C'
stringdef dz`  hex '64 17A'
stringdef rz   hex '72 7A'
stringdef sz   hex '73 7A'

define v 'a{a"}e{e"}o{o"}uy{ia}{ia"}{ie}{ie"}{io}{io"}{iu}i'

static const unsigned char g_v[] = { 17, 65, 16, 1, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 4, 0, 16, 0, 0, 1 };

how i can use digraphs in stemmer?