Can be not that easy if the envelope uses 3C/3D functions. If the dongle is HASP4 those functions are used for sure. These functions are used for code decription using the algorithm stored in the dongle, but usually they decrypt only a couple bytes and everythig else is a software algo. 3C is encryption, 3D - decryption function. You can built protection crypting throu the dongle.

The envelope usually contains a couple HASPSEED calls and a 3C/3D stuff. Also there can be some reads from the donlge memory. You can found the HASP API calls using bpx FreeEnvironmentStringsA in Sice. AX is function number as I remember.