Equivalent to VB.Net's Chr() or C's (char)i in CRM Script

Hi,

Is there an equivilent in CRMScript to VB's Chr() where you can obtain a character from its ASCII code.  I think the C equivelent is (char)i.  But I cannot see how to do this is CRM Script.  Bascially I need to change all instances of one character in a string into another character, but the original character is unprintable.  I wanted to use the Ascii code to get the find part of the substitution, and replace it with a printable character such as a ~.

Many thanks,

Trevor