user credentials in webservicequery()

Is there any way to gather the username and password from a secure store rather than saving as cleartext.  In this case, we're trying to call an Appian Process Model published as a webservice, and subsequently are exposing a valid Appian user account inside the code.

webservicequery(
wsConfig: a!wsConfig(
wsdlUrl: rule!SCE_WsdlUrl(),
service: cons!_WSDL_SERVICE,
port: cons!_WSDL_PORT,
operation: cons!_WSDL_OPERATION
),
inputVar: {
startRequest: {
username: "some_user",
password: "some_users_password",
caseId_int: ri!caseId
}
}
)