Do you mean:

For instance:
Yr VBA listbox to act as a VB listbox under VB6?

Nope, the VBA listbox in fact all yr VBA controls (ie. controls straight
from the default VBA toolset) are MSForms controls.
The native VB controls are registered differenty, have other eventhandlers
and other propertybags.
Look at a listbox for instance: you can't assign an array to the "List"
property of the native VB listbox to populate it.
Where as a VBA listbox can ...

In other words, you'll have redesign yr UserForm in a new VB Form in Visual
Basic, using the VBA code sequence adapted to VB.
Or you'll have to use the imported UserForm in yr VB app thus using the
MSForms scope of the UserForm in VB.

Krgrds,
Perry