LsaQueryTrustedDomainInfoByName
LsaSetTrustedDomainInfoByName
setup the trust attribute
#define TRUST_ATTRIBUTE_TRUST_USES_RC4_ENCRYPTION     0x00000080
0x80 is what you need to add to the existing attributes
only applicable if the trust type is MIT trust
#define TRUST_TYPE_MIT                  0x00000003