I'm not saying HB couldn't get this to work, but here's what he'd be dealing with: {
. "content": "!msg $[[0]]",
. "inlinerolls": [
. . {
. . . "expression": "[HR(20—(ceil((10)/1e10) + ceil((10)/4)))] 1D20",
. . . "results": {
. . . . "resultType": "sum",
. . . . "rolls": [
. . . . . {
. . . . . . "text": "HR(20—(ceil((10)/1e10) + ceil((10)/4)))",
. . . . . . "type": "L"
. . . . . },
. . . . . {
. . . . . . "dice": 1,
. . . . . . "results": [
. . . . . . . {
. . . . . . . . "v": 19
. . . . . . . }
. . . . . . ],
. . . . . . "sides": 20,
. . . . . . "type": "R"
. . . . . }
. . . . ],
. . . . "total": 19,
. . . . "type": "V"
. . . },
. . . "rollid": "—JbghwS——29c5v977dAJ",
. . . "signature": "00a0ca795f48b2a499e0ac4d8ea0a2b4b1a9c8f8129ab12829ece6ac311d11f130a3631a182e8c8cc0d2d98a7b2f5d028c5df9091afb626864fd73146afcc100"
. . }
. ],
. "playerid": "—JS3qKxIUPHLzSbK24ve",
. "selected": [
. . {
. . . "_id": "—Jb8F8l1nGmAx9fWf8vU",
. . . "_type": "graphic"
. . }
. ],
. "type": "api",
. "who": "The Aaron"
} Mathematical equations inside of labels are not expanded, so he'd have to pull that block and send it to the chat system to evaluate, then use the resultant number.