I don't recall if there's something you can use but its a pretty straightforward script:
var arrParams = Par.split("!!");
var attrToFind = arrParams[0];
var userMskey = arrParams[1];
var IDStore = GetIDStore();
attrValue = uIS_GetValue(userMskey, IDStore, attrToFind);
return attrValue;
===
manager script(ADDN!!%MX_MANAGER%)
EDIT: Just realised you wanted to get the managers attribute. Script edited.