 <ul> <li><a href="http://stackoverflow.com/questions/1159956/how-to-convert-powerbasic-types-to-vb6-types/1160183#1160183">Jim's answer</a> looks good. I'd also suggest looking at the <a href="http://vb.mvps.org/tips/vb5dll.asp" rel="nofollow noreferrer">Microsoft advice</a> on writing C DLLs to be called from VB. Originally released with VB5 but still relevant to VB6. It explains the structure packing etc. </li> <li>EDIT. Also worth a look: VB6 guru Karl Peterson <a href="http://vb.mvps.org/articles/ap199911.asp" rel="nofollow noreferrer">discusses</a> how to deal with structures containing pointers in VB6.</li> </ul>