Follow these steps to enter multi-currency expenses in BillQuick or Web Suite:
1. Set the Expense Currency at the project level, say, to Indian Rupee (INR) with a Current Multiplier of 55 (Forex Conversion: $1= Rs. 55).
2. Set the Home Currency at the Company level to, say US Dollars (USD) with a Current Multiplier of 1.
Note: All the conversions are based on the currency conversion rate set in the Currency Multiplier screen. See the KB article on Setting up foreign currencies in BillQuick.
3. Now, go to Expense Log and enter the Cost in the foreign currency, say Rs. 55. 
BillQuick will convert this cost to your home currency in the Charge Amount field, e.g., $1.17 ( including taxes and markup). The same cost is converted to the foreign currency in the Foreign Amount field, e.g., Rs. 64.13 (including taxes and markup).
Note: Cost Amount does NOT include taxes and markup. This is the value that is seen in the Simple Expense Log grid (an alternative expense entry screen).
4. Save the entry. When you create an invoice, the converted amount is displayed there.
For more, read the Multi-Currency blog article and BillQuick Help file.