(RODBC) defining variable as text

Dear all,

I use the RODBC package to import data from a Microsoft Access
database. When importing the different variables I use a marker, a
unique code which consists of a series of numbers starting with
several (not a fixed number) of zero's. Now the problem is that when I
want to import this data to R with the RODBC package (the used code is
displayed on the bottom of this message) it converts this marker to a
number and cuts of the starting zero's. Is there a possibility to
avoid this?

The code used for importing the data:

library(RODBC)
data <- odbcConnectAccess("testDB")
sqlTables(data)
GDATA = sqlFetch(data,"testdata")
odbcClose(data)

Kind regards,