This OID (rPDULoadStatusLoad=1.3.6.1.4.1.318.1.1.12.2.3.1.1.2) refers to a table. You can still do the transformation but you can get more than one result. Here's the formula:
{rPDULoadStatusLoad}/10
If you are interested only in one specific row from this table you should create GET UnDP for this specific index and then transform it:
UnDP
OID = 1.3.6.1.4.1.318.1.1.12.2.3.1.1.2.1
Name = rPDULoadStatusLoadSingle
SNMP Get Type = GET
Transform
{rPDULoadStatusLoadSingle}/10
