Problem with VB soft

hi! guys started cracking a vb app.

actually it's screensaver coded in VB5 but the main protection lies in a file with a spf extension. The file is not a valid pe file but the check for the serial is made to the scf file when u enter the serial in the screensaver file. just wanted to ask is there a vb5 equivalent for readfile api etc!!!

for serial checking i used three api's --
vbastrcmp
vbavarcmpeq
vbavartsteq

but the app does not use these routines!!!!!!!!
did a search but couldot find anything usefull.

Is there a smartcheck for winxp like for 98?