Hi Christian,
InfoPath can use custom "ActiveX" controls with some caveats - here is some
information that you should find of use:
Lab 6: ActiveX Controls in InfoPath 2003
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odc_ip2003_
tr/html/odc_INF_Lab_06.asp
An ActiveX control does not appear as you expect it to when you add the
control to a form in InfoPath 2003
http://support.microsoft.com/default.aspx?scid=KB;EN-US;891165
BUG: InfoPath 2003 Service Pack 1 stops responding when there is an ActiveX
control with a ReadyState property
http://support.microsoft.com/default.aspx?scid=KB;EN-US;888705
ActiveX controls that perform cross-domain data binding cannot be used in
InfoPath 2003
http://support.microsoft.com/default.aspx?scid=KB;EN-US;892950
I hope this information helps!
Best regards,
Scott L. Heim
Microsoft Developer Support
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