Can I add a lookup field to a web form ?

Can I add a lookup field to a web form ?

We have several sales people on the road. One of the KPI´s they are reporting on is meetings with potential and existing clients.

We have made a custom module called "Meetings" with related lists to "Account" and "Contact". 

The Module contains the following fields:
- Meeting purpose
- Account
- Contact
- Date
- Result/Outcome

We would like to add to this module "on the road". As this is a custome module this can not be done in the iPhone app.
I looked into creating a web form, but the lookup fields "Account" and "Contact" does not shoe in the web form creator?

Is there a way to do this ?