Wrap the int variable passed to RemoveAt() in $(). See code below. I changed the var names as I wasn't sure whether either "temp" or "index" might be reserved words or vars in LabTalk.
dataset dsTemp={1,2,3};
int nIdx = 2;
dsTemp.RemoveAt($(nIdx));
for (int nn = 1; nn <= dsTemp.GetSize(); nn++)
{
type $(dsTemp[nn]);
}