I want to use this proj4 code:
+proj=utm +zone=19 +ellps=WGS84 +toclrk66=-3,142,183,0,0,0,0 +units=m +no_defs
or this one:
+proj=utm +zone=19 +ellps=WGS84 +tonad27=-3,142,183,0,0,0,0 +units=m +no_defs
to make on the fly transformations from WGS84 to NAD27, using the geocentric tanslation parameters recommended for Dominican Republic. I typed this codes using the "New CRS" capacity in QGIS 2.0 (Configuration>Custom CRS), but it doesn't accept the transformation parameters. After typing the codes, and pressing OK, the CRS created looks like this:
+proj=utm +zone=19 +ellps=WGS84 +units=m +no_defs
QGIS deletes the geocentric traslation parameters. Maybe I'm violating proj4 codes rules, and that's why I'm asking for help.