This is a bit late (couple of years), however, it still may be of some benefit.

I too, wanted to programmatically add new methods to a Class Library. After some trial and error, I did find the following WILL work.

* NOTE: CRLF needs to be included, otherwise, when two or more methods are added the format will be incorrect.
REPLACE RESERVED3 WITH '*' + ALLTRIM(LOWER(Thisform.txtcMethodName.Value)) + CHR(13) + CHR(10) ADDITIVE

It does appear that using the following will NOT work:

lcMethodList = ALLTRIM(RESERVED3)
REPLACE RESERVED3 WITH lcMethodList + '*' + ALLTRIM(LOWER(Thisform.txtcMethodName.Value))

Obviously the key is using ADDITIVE