Here are some more variations for posterity.
Multiple ValueIns and how to use them
{
"options": {
"valueIn": [
{
"orderNum": "{ShipDtl.OrderNum}"
},
{
"orderLine": "{ShipDtl.OrderLine}"
},
{
"orderRel": "{ShipDtl.OrderRelNum}"
},
{
"partNum": "{ShipDtl.PartNum}"
},
{
"packNum": "{ShipDtl.PackNum}"
},
{
"qty": "{ShipDtl.DisplayInvQty}"
}
],
"callBackToken": "partbinorder"
}
}
On the launched form side, hook into some event and use row-update to set your fields to the values using this syntax.
%session.context.initialValueIn.ValueIn[0].orderNum%
%session.context.initialValueIn.ValueIn[1].orderLine%
%session.context.initialValueIn.ValueIn[2].orderRel%
%session.context.initialValueIn.ValueIn[3].partNum%