You could use filter to get the base and “special” parameters:
class MyModel(nn.Module):
    def __init__(self):
        super(MyModel, self).__init__()
        self.conv1 = nn.Conv2d(3, 6, 3, 1, 1)
        self.pool1 = nn.MaxPool2d(2)
        self.conv2 = nn.Conv2d(6, 12, 3, 1, 1)
        self.pool2 = nn.MaxPool2d(2)
        self.fc1 = nn.Linear(12*56*56, 128)
        self.fc2 = nn.Linear(128, 10)
        
    def forward(self, x):
        x = F.relu(self.conv1(x))
        x = self.pool1(x)
        x = F.relu(self.conv2(x))
        x = self.pool2(x)
        x = x.view(x.size(0), -1)
        x = F.relu(self.fc1(x))
        x = self.fc2(x)
        return x

        
model = MyModel()

my_list = ['fc1.weight', 'fc1.bias']
params = list(filter(lambda kv: kv[0] in my_list, model.named_parameters()))
base_params = list(filter(lambda kv: kv[0] not in my_list, model.named_parameters()))

Depending on your model definition (custom vs. nn.Sequential etc.) some other code snippets might be prettier. Let me know, if that works for you.