I haven't done it myself, but Ángel Martin's 41Z module can do it, and maybe also his SandMath, Sandbox, and/or other such modules he has done. His 41Z module is one I'm looking forward to using. It's mainly for complex-number operations-- and it has tons-- about 70, including all the comparisons, stack operations (with all the indirects!), roots, hyperbolics, ZAVIEW (the "Z" meaning "complex"), geometry, etc.! The Advantage module has complex-number operations, but it's pretty clumsy compared to the 41Z. The 41Z gives another keyboard, an additional user keyboard if I understand it correctly, in order to make it quicker to reach all the complex-number functions, and another shift key, the old Σ+ key which almost no one uses except by re-assigning it. It gives a true 4-level complex stack, plus a complex LastX, if I understand it correctly. The Advantage module only used the native stack, limiting you to two levels when it does complex numbers. Ángel is a genius in math and HP-41 assembly-language programming. And between the new software modules and the MLDL-2000, Clonix41, NoVRAM, 41CL, and other such pieces of hardware being introduced, the future for the 41 looks really good! I can't give you any more details (I need to get them myself, for my own use) but hopefully this will get your search going.
Clonix41, NoVRAM, NoV-32, NoV-64: http://www.clonix41.org/
41CL (much faster hardware implant in your 41!): http://systemyde.com/pdf/sy41cl_v3.pdf