Hi David, thank's for your help.
The activeX expected a 16-bit integer, so
I tried to do that :

x=bintoc(100,2)
activeX.Method(@x)

The same error ( Type missmach ) occurs.

And i tried to do that :
x=bintoc(100,2)
createbinary(x)
activeX.Method(@x)

Same error..
Any idea ?
Thank's again.
Lucas