Hi Douglas Gerard,
I understand you want to invoke a function present inside a DLL file into MALTAB.
LOADLIBRARY function in MALTAB can be used to load a DLL into MALTAB and call functions present inside the DLL.
More information on LOADLIBRARY can be found in the links below:
The below thread on MALTAB Central can also be useful:
Hope this helps.
Thanks
Sudhanshu Bhatt