VBA Excel replace strings in active cells

Hi,

I am writing a VBA macro for Excel where I need to replace a template string with another value.

For example, a cell may contain the following text : "{Username} processed the delivery on {DeliveryDate}."

Any of the active cells in the worksheet may have one or more of the template strings.

The template strings are to be replaced by actual values entered into a userform.

Is there an easy way to do the replacament (eg. "{Username}" with "John") in all the active cells, other than cycling through each cell (ie. using a replace all function would be really good, but I dont know how to do it in VBA).

Any suggestions appreciated

Greg