Adding an address as a pointer with an offset

[jsmars]

I know this isn't maintained, but I'm hoping someone sees this and can answer.

How can I call iAddAddressManually and successfully specify a Pointer with an offset, as I can do in the Cheat Engine application? Is there some kind of syntax for this or is there a better way? Also I'm using a registeredsymbol, which does work as an address directly, but what I'd like is to make it a pointer so that my address is the value of my symbol + an offset.

ex.)
Address: HP_BaseAddress, Value: 029A4674
Address: HP_BaseAddress+78, Value: 100 (address is actually 29A46EC)