If you have a set of measures and some of them are US dollars, some are Euros, and some are UK Pounds, you want to format them correctly in SSAS.
First you will need to know the ASCII command to type a pound and euro symbol. You can find this in the character map in windows. You must use the 10 key number pad to type these in while holding down ALT.
Euro = Alt + 0128 €
Pound = Alt + 0163 £
Next you will need to put a back slash in the format string before the symbol for it to show up in excel.
Here are the images from SSAS:
\£ #,##0.00;(\£ #,##0.00)
#,##0.00 \€;(#,##0.00 \€)
Here is the image from Excel: